提前預(yù)判考點(diǎn)態(tài)度易考多次出現(xiàn)noun

考舉例論證考類(lèi)比論證考對(duì)比論證考03舉例可跳，重點(diǎn)在舉例目的并列段

,

Second,

Third

可在做題時(shí)再看把文章讀少02不出主旨題和組織結(jié)構(gòu)題，可以不讀全文出主旨題和組織結(jié)構(gòu)題，時(shí)間緊讀Paragraph1，opening

sentence,

and

thewrap

sentence題目和時(shí)間決定讀文章的程度和順序01長(zhǎng)閱讀解題要點(diǎn)

460

7

4第1

篇文藝復(fù)興建筑1】閱讀題干1.

The

passage

is

primarily

concernedwith判定為：全文主旨題短文章主旨題的解法立論駁論定基調(diào)四種結(jié)構(gòu)找位置事實(shí)觀點(diǎn)常考點(diǎn)4.修飾關(guān)系嚴(yán)把Argument

vs

Presentation主旨句Fact

vs

Theoryestablished,

universally

accepted2.

It

can

be

inferred

from

the

passage

that

the

author

believesthat

which

of

the

following

is

true

of

painting

and

architectureof

the

Baroque

era?判定為：推斷題有效定位詞：名詞，時(shí)間詞Painting/architectureof

the

Baroque

Era文藝復(fù)興建筑1】閱讀題干推斷題的三種考法正向推斷原文的信息改寫(xiě)（找-回-改）Afew(F) Majority

(NOT

F)取反推斷數(shù)量取反時(shí)間取反特殊詞性since

1970s

(F)

after

1970s

(NOT

F)Warm

vs

Cold長(zhǎng)文章中的偶有多段落定位舉例：題干中有某詞“*”長(zhǎng)文章中有兩段都有“*”往往前段講內(nèi)容后段講用途和處境文藝復(fù)興建筑1】閱讀題干3.

The

author’s

mention

ofFlorentine

painting

serves

in

the

context

of

thepassage

to

support

which

of

the

followingassertions?判定題型：信息目的題可定位詞：Florentine

painting文藝復(fù)興建筑1】閱讀題干信息目的題（問(wèn)作者寫(xiě)作意圖）1.考點(diǎn)同舉例目的題Q：為什么提到這個(gè)信息A:

是該信息的邏輯的上一層定位句：

如果劃線信息很短，答案可能就在劃線的句子里如果劃線信息長(zhǎng)，

答案可能

句（后句）2作者評(píng)價(jià)或態(tài)度Q：根據(jù)這個(gè)信息作者會(huì)同意以下哪個(gè)觀點(diǎn)A：是作者原文評(píng)價(jià)的同義替換偶見(jiàn)難題：A

B

信息并列定位找到作者對(duì)A

態(tài)度，問(wèn)對(duì)B態(tài)度文藝復(fù)興建筑1】閱讀題干4.

The

passage

suggests

which

of

the

following

aboutthecited

“scholars”?判定為：推斷題suggest,infer,imply有效定位詞：scholars文藝復(fù)興建筑1】閱讀題干文藝復(fù)興建筑（101篇Passage

33）A

primary

value

in

early

twentieth-century

Modernist

architectural

theory

was

thatof

“truth

to

materials”,

that

is,

it

was

essential

that

a

building’s

design

express

the“natural”

character

of

the

building

materials.

This

emphasis

would

have

puzzledthe

architects

of

the

Italian

Renaissance

(sixteenth

century),

riod

widelyregarded

as

the x

of

architectural

achievement,

for

Renaissance

architects’designs

were

determined

only

minimally

by

the

materials

employed.

The

diversityof

Italy’s

natural

resources

provided

Renaissance

architects

with

a

wide

variety

ofbuilding

materials.

The

builders

of

the

Pitti

Palace

(1558-1570)

used

great

blocks

ofTuscan

stone,

just

as

Etruscans

living

in

the

same

part

of

Italy

had

done

sometwenty

centuries

earlier.

Had

the

Florentine

Renaissance

builders

d

theEtruscan

style,

it

might

be

said

that

their

materials

determined

their

style,

sinceEtruscan

style

matched

the

massive,

stark,

solid

character

of

the

stone.

But

thesesame

materials,

which

so

suited

the

massive

Etruscan

style,

were

effectively

usedby

the

Florentine

Renaissance

to

create

the

most

delicate

and

graceful

of

styles.（待續(xù)）找到首段

對(duì)象16th

Century

Italian

RenaissanceArchitectural對(duì)象作找到首段者態(tài)度x語(yǔ)義線索20、16世紀(jì)比較

Tuscan

StoneMatch

/

Effectively

useA

similar

example

of

identical

materials

used

incontrasting

styles

characterizes

the

treatment

of

Romantravertine

marble.

When

Baroque

architects

ofseventeenth-century

Rome

desired

a

massive

and

solidmonumental

effect,

they

turned

to

travertine

marble,whose

“natural

effect”

is,

indeed,

that

of

spaciousbreadth

and

lofty,

smoothly

rounded

surfaces.

Yet

duringthe

Renaissance,

this

same

material

had

been

usedagainst

its

“nature,”

in

the

Florentine

tradition

of

sharplycarved

detail.次段首句A

similar

exampleIdentical

materialsContrasting

styles挖掘舉例目的引出17世紀(jì)Baroque

architects看段內(nèi)新舊概念切換的地方Y(jié)etItalian

Renaissance

architecture

was

sh

d

less

by

the“nature”

of

the

materials

at

hand

than

by

the

artisticmilieu

of

Renaissance

Italy,

which

included

painting

andsculpture

as

well

as

architecture.

While

Romantravertine

marble

may

have

lent

itself

to

fine

carving,the

Florentine

passion

for

fine

detail

is

no

less

markedin

Florentine

Renaissance

painting

than

in

FlorentineRenaissance

architecture.

Similarly,

in

the

next

century,the

emphasis

on

shading

and

corporeal

density

inBaroque

painting

mirrored

the

use

of

Roman

travertinemarble

in

Baroque

architecture

to

create

broad

shadowand

powerfulmasses.讀懂次段首句Less

by

A

than

by

B句子目的挖掘

找尋真正的原因特殊的語(yǔ)言現(xiàn)象

A

and

B

as

well

as

CLess

by

A

than

by

BNo

less

thanSimilarly看段內(nèi)新舊概念切換的地方SimilarlyThe

ingenuity

of

Renaissance

architects

extended merely

using

a

material

in

away

not

suggested

by

its

outward

natural

appearance.

If

they

conceived

a

design

thatcalled

for

a

certain

material

either

too

expensive

or

difficult

to

work

with,

they

madeno

scruple

about

imitating

that

material.

Their

marbles

and

their

stones

are

oftenactually

painted

stucco.

When

the

blocks

of

masonry

with

which

they

built

were

not

inscale

with

the

projected

scheme,

the

real

joints

were

concealed

and

false

onesintroduced.

Nor

were

these

practices

confined,

as

some

scholars

insist,

to

the

later

andsupposedly

decadent

phases

of

the

art

Material,

then,

was

utterly

subservient

to

style.20th主流理論：

建筑設(shè)計(jì)

材料16th

設(shè)計(jì)很少局限于建材Eg.Etruscans匹配20世紀(jì)早期Eg.Baroque17世紀(jì)T-marbleEg.

Pitti

PalaceEg.文藝復(fù)興時(shí)T-marbleagainst

its

nature16藝術(shù)環(huán)境-繪畫(huà)風(fēng)格17Baroque繪畫(huà)mirror建筑R建筑擴(kuò)展–模仿，引入假joints建筑屈從于風(fēng)格1.

The

passage

is

primarily

concerned

withA.explaining

thedifferences

in

quality

among

different

kindsof

building

materialsB.

discussing

the

differences

among

Etruscan,

FlorentineRenaissance,

and

Roman

Baroque

architectureC.describing

how

different

materials

influenced

architecturein

different

citiesD.describing

the

manner

in

which

Renaissance

architectsoften

resorted

to

artificial

materials

and

illusionistic

effectsE.demonstrating

the

attitude

of

sixteenth-

and

seventeenth-century

Italian

architects

toward

the

use

of

building

materials藝術(shù)風(fēng)格和材料的關(guān)系2.Itcan

be

inferred

from

the

passage

that

the

author

believesthat

which

of

the

following

is

true

of

paintingand

architectureof

the

Baroqueera?Both

emphasize

the

“natural”

use

of

materials.Both

are

derived

from

the

Florentine

Renaissance

style.Both

have

been

overlooked

by

twentieth-centuryModernists.They

have

certain

visual

features

in

common.They

illustrate

the

degeneration

ofa

style.A.有瑕疵,建筑風(fēng)格是一致的，但是繪畫(huà)風(fēng)格沒(méi)有明確表明，因而不算完美The

author’s

mention

of

Florentine

painting

serves

in

the

context

of

thepassage

to

support

which

of

the

following

assertions?The

constraints

that

operate

in

architecture

are

different

from

those

thatoperate

in

paintingFlorentine

architectural

style

was

not

determinedby

the

nature

oftheavailable

marble.The

Florentine

Renaissance

period

was riod

in

which

the

other

artsachieved

the

same

distinction

as

did

architecture.Technical

advances

in

all

ofthe

arts

ofthe

Florentine

Renaissancedetermined

the

stylistic

qualities

of

those

arts.Native

preferences

of

style

do

not

manifest

themselves

in

the

same

waysindifferent

arts.4.

The

passage

suggests

which

of

the

following

about

the

cited

“scholars”?A.They

believe

thata

decadent

phase

is

characteristic

of

any

significant

artisticmovement.They

reject

the

popular

view

ofthe

Renaissance

as

the x

ofarchitecturalachievement.They

believe

that

a

vigorous

and

healthy

architecture

would

notusuallyemploy

false

surfaces

or

imitation

building

materials.They

represent

the

mainstream

in

critical

and

historical

thought

about

theFlorentine

Renaissance.They

have

focused

on

such

technical

matters

as

the

cost

of

building

materialsrather

than

on

artistic

concerns.Nor

were

these

practices

confined,

assome

scholarsinsist,

to

the

later

andsupposedly

decadent

phases

of

the

artMaterial,

then,

was

utterly

subservientto

style.期屈從于風(fēng)格The

primary

purpose

of

the

passage

is

tocorrect

some

misinterpretations

about

the

development

of

an

architecturalformcompare

the

traditional

church

architectures

of

two

different

culturesexaminethe

influence

of

a

religious

architectural

style

on

secularbuildingsexplain

the

nature

of

the

contrast

between

two

different

architectural

stylestrace

the

European

roots

of

an

architectural

style

used

in

the

United

Stales第2

篇新墨西哥州殖民建筑（101篇Passage

35）Architectural

morphology

is

the

study

of

how

shifting

cultural

andenvironmental

conditions

produce

changes

in

an

architectural

form.When

applied

to

the

mission

churches

of

New

Mexico

exemplifyingseventeenth-

and

eighteenth-century

Spanish

colonial

architecturein

what

is

now

the

southwestern

United

States,

architecturalmorphology

reveals

much

about

how

Native

American

culturetransformed

the

traditional

European

church

architecture

of

theSpanish

missionaries

who

hoped

to

convert

Native

Americans

toChristianity.Many

studies

of

these

mission

churches

have

carefully

thehistory

and

design

of

their

unique

architectural

form,

most

attribute

thechurches’

radical

departure

from

their

sixteenth-century

Europeanpredecessors

to

local

climate

and

a

less-mechanized

building

technology.Certainly,

the

limitations

imposed

by

manual

laborand

the

locally

availablematerials

of

mud-brick

and

timber

necessitated

a

divergence

from

theoriginal

European

chur

odel.

However,

the

emergence

of

a

churchform

suited

to

life

in

the

Southwest

was

rooted

in

something

morefundamental

than

material

and

technique.

The

new

architecture

resultedfrom

cultural

forces

in

both

the

Spanish

colonial

and

indigenous

NativeAmerican

societies,

each

with

competing

ideas

about

form

and

space

anddifferent

ways

of

conveying

these

ideas

symbolically.For

example,

the

mission

churches

share

certain

spatial

qualities

with

theindigenous

kiva,

a

round,

partly

subterranean

room

used

by

many

SouthwestNative

American

communities

for

important

rituals.Likethekiva

it

was

intended

toreplace,

the

typical

mission

church

had

thick

walls

of

adobe

(sun-dried

earth

andstraw),

a

beaten-earth

floor,

and

one

or

two

small

windows.

In

deference

toEuropean

custom,

the

ceilings

of

these

churches

were

higher

than

those

of

thetraditional

kiva.

However,

with

the

limited

lighting

afforded

by

their

few

smallwindows,

these

churches

still

suggest

the

kiva's

characteristically

low,

boxlike,earth-hugging

interior.

Thus,

although

pragmatic

factors

of

construction

may

havecontributed

to

the

sh

of

the

mission

churches,

as

earlier

studies

suggest,

theprovision

of

a

sacred

space

consistent

with

indigenous

traditions

may

also

havebeen

an

important

consideration

in

their

design.The

continued

viability

of

the

kiva

itself

in

Spanish

mission

settlements

has

also

beenunderestimated

by

historians.

Freestanding

kivas

discovered

in

the

ruins

of

European-stylemissionary

communities

have

been

explained

by

some

historians

as

examples

of“superposition”.

Under

this

theory,

Christian

domination

over

indigenous

faiths

isdramatized

by

surrounding

the

kivawith

Christian

buildings.

However,

as

James

Iveypointsout,

such

superposition

was

unlikely,

since

historical

records

indicate

that

most

Spanishmissionaries,

arriving

in

the

Southwest

with

little

or

no

military

support,

wisely

adopted

asomewhat

conciliatory

attitude

toward

the

use

of

the

kiva

at

least

initially.

This

fact,

andthe

careful,

solitary

placement

of

the

kiva

in

the

center

of

the plex

courtyards,suggests

an

intention

to

highlight

the

importance

of

the

kiva

rather

than

to

diminish

it.The

passage

suggests

that

the

indicated

historians

regarded

the

placement

ofkivas

in

the

midst

of

Christian

buildings

as

which

of

the

following?exemplary

of

an

arrangement

of

religiousbuildings

typical

of

a

kind

ofNativeAmerican

architecture

common

prior

to

the

arrival

of

theSpanishlargely

responsible

for

the

evolution

of

adistinctive

Spanish

mission

architecturalstyleindicative

of

the

Spanish

missionaries’

desire

to

display

an

attitude

of

acceptancetoward

the

kivasymbolic

of

the

controversy

among

Spanish

missionaries

in

New

Mexico

regardingtheir

treatment

of

the

indigenous

populationreflective

of

the

Spanish

missionary’s

desire

to

diminish

the

kiva's

importanceThe

continued

viability

of

the

kiva

itself

in

Spanish

mission

settlements

has

alsobeen

underestimated

by

historians.Freestanding

kivas

discovered

in

the

ruins

of

European-style

missionarycommunities

have

been

explained

by

some

historians

as

examples

of“superposition”.Under

this

theory,

Christian

domination

over

indigenous

faiths

is

dramatized

bysurrounding

the

kiva

with

Christian

buildings.3.Which

of

the

following,

if

true,

would

most

strengthen

the

argument

about

theSpanish

missionaries’

attitude

toward

the

kiva?A.The

period

of

most

intensive

settlement

by

Spanish

missionaries

in

theSouthwest

occurred

before

the

period

in

which

the

mission

churches

of

NewMexico

werebuilt.B.There

are

no

traces

of

kivas

in

Spanish

mission

settlements

that

were

protectedby

a

large

militarypresence.tle

of

the

secular

Spanish

colonial

architecture

of

the

Southwest

of

theseventeenth

and

eighteenthcenturiesispredominantly

European

instyle.D.Some

Spanish

missionary

communities

of

the

seventeenth

and

eighteenthcenturies

were

attached

to

Spanish

military

installations.E.New

Mexico

contains

by

far

the

largest

concentration

ofSpanish

mission-stylechurch

architecture

in

theUnited

States.新墨西哥州殖民建筑（101篇Passage

35）Architectural

morphology

is

the

study

of

how

shifting

cultural

andenvironmental

conditions

produce

changes

in

an

architectural

form.When

applied

to

the

mission

churches

of

New

Mexico

exemplifyingseventeenth-

and

eighteenth-century

Spanish

colonial

architecturein

what

is

now

the

southwestern

United

States,

architecturalmorphology

reveals

much

about

how

Native

American

culturetransformed

the

traditional

European

church

architecture

of

theSpanish

missionaries

who

hoped

to

convert

Native

Americans

toChristianity.The

continued

viability

of

the

kiva

itself

in

Spanish

mission

settlements

has

also

beenunderestimatedby

historians.

Freestanding

kivas

discovered

in

the

ruins

of

European-stylemissionary

communities

have

been

explained

by

some

historians

as

examples

of“superposition”.

Under

this

theory,

Christian

domination

over

indigenous

faiths

isdramatized

by

surrounding

the

kivawith

Christian

buildings.

However,

as

James

Iveypointsout,

such

superposition

was

unlikely,

since

historical

records

indicate

that

most

Spanishmissionaries,

arriving

in

the

Southwest

with

little

or

no

military

support,

wisely

adopted

asomewhat

conciliatory

attitude

toward

the

use

of

the

kiva

at

least

initially.

This

fact,

andthe

careful,

solitary

placement

of

the

kiva

in

the

center

of

the plex

courtyards,suggests

an

intention

to

highlight

the

importance

of

the

kiva

rather

than

to

diminish

it.4.According

to

thepassage,

the

building

techniques

prevailing

in

the

Southwest

duringtheseventeenth

and

eighteenth

centuries

played

a

role

in

which

of

the

following?A.preventing

missionaries

in

the

Southwest

from

duplicating

traditional

Europeanchurchesinfluencing

missionaries

in

the

Southwest

to

incorporate

a

freestanding

kiva

into

certainmissionsettlementscausing

missionaries

in

the

Southwest

to

limit

the

building

of

churches

to

New

Mexicoonlyjeopardizingthe

viability

of

Spanish

religious

settlements

throughout

the

Southwestencouraging

many

missionaries

inthe

Southwest

to

reexaminethe

continued

viability

ofa

highly

ceremonialEuropean

religious

tradition第3

篇According

to

the

passage,

which

of

the

following

is

true

of

thecollisions

mentionedin

the

highlightedsentence?事實(shí)信息題（1st

collisions）The

author

of

the

passage

asserts

which

of

the

following

abouttitanic

collision

models?態(tài)度題（titanic

collision

models

）The

passage

suggests

that

which

of

the

following

is

true

of

the

citedcompounds

and

elements?推斷題（compounds

and

elements）In

the

second

paragraph,

the

author

is

primarily

concerned

with段落主旨題（2nd

）月球（101篇Passage

18）Massive

projectiles

striking

much

larger

bodies

create

various

kinds

of

craters,

including

multi-ring

basins–the

largest

geologic

features

observed

on

planets

and

moons.

In

such

collisions,

theimpactor

is

comple

y

destroyed

and

its

material

is

incorporated

into

the

larger

body.

Collison’sbetween

bodies

of

comparable

size,

on

the

other

hand,

have

very

different

consequences:

one

orboth

bodies

might

be

entirely

smashed,

with

mass

from

one

or

both

the

bodies

redistributedamong

newobjects

formed

from

the

fragments.

Such

a

titanic

collision

betweenEarth

and

a

Mars-sizeimpactor

may

have

givenrise

to

Earth’s

Moon.The

Earth-Moon

system

has

always

been

perplexing.

Earth

is

the

only

one

of

the

inner

planetswith

a

large

sa

lite,

the

orbit

of

which

is

neither

in

the

equatorial

plane

of

Earth

nor

in

the

planein

which

the

other

planets

lie.

The

Moon’s

mean

density

is

much

lower

than

that

of

Earth

but

isabout

the

same

as

that

of

Earth’s

mantle.

This

similarity

in

density

has

long

prompted

speculationthat

the

Moonsplitaway

fromarapidly

rotatingEarth,

but

this

ideafounders

on

two

observations.In

order

to

spin

off

the

Moon,

Earth

would

have

had

to

rotate

so

fast

that

a

day

would

have

lastedless

than

three

hours.

Science

offers

no

plausible

explanation

of

how

it

could

have

slowed

to

itscurrent

rotational

ratefrom

thatspeed.

Moreover,

the

Moon’scomposition,

though

similar

to

thatof

Earth’s

mantle,

is

not

a

precise

match.

Theorizing

a

titanic

collision

eliminates

postulating

a

too-rapidly

spinning

Earth

and

accounts

for

the

Moon’s

peculiar

composition.

In

a

titanic

collisionmodel,

the

bulk

of

the

Moon

would

have

formed

from

a

combination

of

material

from

theimpactor

and

Earth’s

mantle.

Most

of

the

earthly

component

would

have

been

in

the

form

ofmelted

or

vaporized

matter.

The

difficulty

in

recondensing

this

vapor

in

Earth’s

orbit,

and

itssubsequent

loss

to

the

vacuum

of

outer

space,

might

account

for

the

observed

absence

in

lunarrocks

of

certain

readily

vaporized

compounds

and

elements.

Unusual

features

of

some

otherplanets

might

also

be

explained

by

such

impacts.

Mercury

is

known

to

have

a

high

density

incomparison

with

other

rocky

planets.

A

titanic

impact

could

have

stripped

away

a

portion

of

itsrocky

mantle,

leaving

behind

a

metallic

core

whose

density

is

out

of

proportion

with

the

originalratio

of

rock

to

metal.

A

massive,

glancing

blow

to

Venus

might

have

given

it

its

anomalously

slowspin

and

reversed

direction

of

rotation.

Such

conjectures

are

tempting,

but,

since

no

early

planetwas

immune

to

titanic

impacts,

they

could

be

used

indiscrimina

y

to

explain

away

in

a

cavalierfashion

every

unusual

planetary

characteristic;

still,

we

may

now

be

beginning

to

discern

the

truerole

oftitanic

impacts

in

planetary

history.月球（101篇Passage

18）①M(fèi)assive

projectiles

striking

much

larger

bodies

create

variouskinds

of

craters,

including

multi-ring

basins–the

largest

geologicfeatures

observed

on

planets

and

moons.

②In

such

collisions,

theimpactor

is

comple

y

destroyed

and

its

material

is

incorporatedinto

the

larger

body.

③Collison’s

between

bodies

of

comparablesize,

on

the

other

hand,

have

very

different

consequences:

one

orboth

bodies

might

be

entirely

smashed,

with

mass

from

one

or

boththe

bodies

redistributed

among

new

objects

formed

from

thefragments.

④Such

a

titanic

collision

between

Earth

and

a

Mars-sizeimpactor

may

have

given

rise

to

Earth’s

Moon.詳細(xì)閱讀首段判斷寫(xiě)作對(duì)象是？月球

（101篇Passage

18）The

Earth-Moon

system

has

always

been

perplexing.⑴Earth

is

theonly

one

of

the

inner

planets

with

a

large

sa

lite,the

orbit

ofwhich

is

neither

in

the

equatorial

plane

of

Earth

nor

in

the

plane

inwhich

the

other

planets

lie.

⑵The

Moon’s

mean

density

is

muchlower

than

that

of

Earth

but

is

about

the

same

as

that

of

Earth’smantle.

This

similarity

in

density

has

long

prompted

speculationthat

the

Moon

split

away

from

a

rapidly

rotating

Earth,but

this

ideafounders

on

two

observations.⑴In

order

to

spin

off

the

Moon,Earth

would

have

had

to

rotate

so

fast

that

a

day

would

have

lastedless

than

three

hours.Science

offers

no

plausible

explanation

ofhow

it

could

have

slowed

to

its

current

rotational

rate

from

thatspeed.（續(xù)）看二段與首段承上啟下句子查找段內(nèi)切換 對(duì)象的節(jié)點(diǎn)Founder

on

破壞，摔倒Have

to

削弱Plausible

貌似的月球

（101篇Passage

18）⑵Moreover,

the

Moon’s

composition,

though

similar

to

that

ofEarth’s

mantle,

is

not

a

precise

match.

Theorizing

a

titanic

collision

eliminates

postulating

a

too-rapidly

spinning

Earth

and

accounts

for

the

Moon’s

peculiar

composition.Theorize

建立…的理論P(yáng)ostulate假定月球

（101篇Passage

18）In

a

titanic

collision

model,

the

bulk

of

the

Moon

would

haveformed

from

a

combination

of

material

from

the

impactor

andEarth’s

mantle.

Most

of

the

earthly

component

would

have

been

inthe

form

of

melted

or

vaporized

matter.

The

difficulty

inrecondensing

this

vapor

in

Earth’s

orbit,

and

its

subsequent

loss

tothe

vacuum

of

outer

space,

might

account

for

the

observed

absencein

lunar

rocks

of

certain

readily

vaporized

compounds

and

elements.月球（101篇Passage

18）Unusual

features

of

some

other

planets

might

also

be

explained

bysuch

impacts.

Mercury

is

known

to

have

a

high

density

incomparison

with

other

rocky

planets.

A

titanic

impact

could

havestripped

away

a

portion

of

its

rocky

mantle,

leaving

behind

ametallic

core

whose

density

is

out

of

proportion

with

the

originalratio

of

rock

to

metal.

A

massive,

glancing

blow

to

Venus

might

havegiven

it

its

anomalously

slow

spin

and

reversed

direction

of

rotation.Such

conjectures

are

tempting,

but,

since

no

early

planet

wasimmune

to

titanic

impacts,