托福阅读生物类背景知识及真题

珊瑚礁珊瑚礁(coral

reef)

岩体。珊瑚礁的主体是由珊瑚虫(polyp)组成的。珊瑚虫是海洋中的出石灰石(limestone)，变为自己生存的外壳。每一个单体的珊瑚虫这些石灰石经过以后的压实、石化，形成岛屿和礁石，也就是所谓的珊瑚礁(coral

reef)

。达尔文根据礁体与岸线的关系，划分出岸礁

(fringing

reef)

、堡礁(barrier

reef)fringing

reef暗礁边缘礁。现代最长的岸礁沿红海沿岸发育，绵延约2700

多公里，分布水深约

36

米。中国台湾恒春半岛和海南岛沿岸也有岸礁发育。barrier

reef堡礁又称堤礁，是离岸有一定距离的堤状礁体，它与陆地隔以泻湖

(环礁湖)(lagoon)。现代规模最大的堡礁是澳大利亚昆士兰大堡礁，全长

约

2000

公里，分布水深约30

米。atoll环礁在几百米至几十公里，形态多样。已知的环礁有

330

个之多,主要分上，孤立于汪洋大海之中，展布受洋底火山(volcano)作用的控制，某些也可在大陆架(continental

shelf)上见到。环礁礁坪上常有灰砂(砾)岛或礁岩岛，统称为珊瑚岛。在

1800

平方公里以上，是世界上最大的两个环礁。南海发育的环礁颇具特色，有泻湖全被封闭的玉琢礁;有泻湖与外海有

3

个通道的华光礁;还有多通道开放式的永乐环礁，半月形全开放式的宣德环礁。永兴岛，面积

1.85

平方公里。托福阅读真题练习：蝴蝶托福阅读文本：Butterflies

are

among

the

most

extensively

studied

insects

—it

is

estimated

that

90

percent

of

the

worlds

species

havescientific

names.

As

a

consequence,

they

are

perhaps

the

bestgroup

of

insects

for

examining

patterns

of

terrestrial

bioticdiversity

and

distribution.

Butterflies

also

have

a

favorable

image

with

the

general

public.

Hence,

they

are

an

excellentgroup for communicating information on science andconservation

issues

such

as

diversity.Perhaps

the

aspect

of

butterfly

diversity

that

has

received

themost

attention

over

the

past

century

is

the

striking

differencein

species

richness

between

tropical

and

temperate

regions.For

example,

in

1875

one

biologist

pointed

out

the

diversity

ofbutterflies

in

the

Amazon

when

he

mentioned

that

about

700species

were

found

within

an

hours

walk,

whereas

the

totalnumber

found

on

the

British

islands

did

not

exceed

66,

andthe whole of Europe supported only 321. This earlycomparison

of

tropical

and

temperate

butterfly

richness

hasbeen

well

confirmed.A

general

theory

of

diversity

would

have

to

predict

not

onlythis

difference

between

temperate

and

tropical

zones,

but

alsopatterns

within

each

region,

and

how

these

patterns

varyamong

different

animal

and

plant

groups.

However,

forbutterflies,

variation

of

species

richness

within

temperate

ortropical regions, rather man between them, is poorlyunderstood.

Indeed,

comparisons

of

numbers

of

speciesamong

the

Amazon

basin,

tropical

Asia,

and

Africa

are

stillmostly

personal

communication

citations,

even

for

vertebrates.

In

other

words,

unlike

comparison

between

temperate

andtropical

areas,

these

patterns

are

still

in

the

documentationphase.In

documenting

geographical

variation

in

butterfly

diversity,some

arbitrary,

practical

decisions

are

made.

Diversity,

numberof

species,

and

species

richness

are

used

synonymously;little

isknown

about

the

evenness

of

butterfly

distribution.

The

NewWorld

butterflies

make

up

the

preponderance

of

examplesbecause

they

are

the

most

familiar

species.

is

hoped

that

byfocusing

on

them,

the

errors

generated

by

imperfect

andincomplete

taxonomy

will

be

minimized.托福阅读题目：1.

Which

aspect

of

butterflies

does

the

passage

mainly

discuss?(A)

Their

physical

characteristics(B)

Their

names(C)

Their

adaptation

to

different

habitats(D)

Their

variety2.

The

word

consequence

in

line

2

is

closest

in

meaning

to(A)

result(B)

explanation(C)

analysis(D)

requirement

3. Butterflies are

a good example

for communicatinginformation

about

conservation

issuesbecause

they(A)

are

simple

in

structure(B)

are

viewed

positively

by

people(C)

have

been

given

scientific

names(D)

are

found

mainly

in

temperate

climates4.

The

word

striking

in

line

8

is

closest

in

meaning

to(A)

physical(B)

confusing(C)

noticeable(D)

successful5.

The

word

exceed

in

line

11

is

closest

in

meaning

to(A)

locate(B)

allow(C)

go

beyond(D)

come

close

to6.

All

of

the

following

are

mentioned

as

being

important

partsof

a

general

theory

of

diversity

EXCEPT(A)

differences

between

temperate

and

tropical

zones(B)

patterns

of

distribution

of

species

in

each

region(C)

migration

among

temperate

and

tropical

zones

(D)

variation

of

patterns

of

distribution

of

species

amongdifferent

animals

and

plants7.

The

author

mentions

tropicalAsia

in

lines

19

as

an

exampleof

a

location

where(A)

butterfly

behavior

varies

with

climate(B)

a

general

theory

of

butterfly

diversity

has

not

yet

beenfirmly

established(C)

butterflies

are

affected

by

human

populations(D) documenting plant species is more difficult thandocumenting

butterfly

species8.

Which

of

the

following

is

NOT

well

understood

by

biologists?(A)

European

butterfly

habitats(B)

Differences

in

species

richness

between

temperate

andtropical

regions(C)

Differences

in

species

richness

within

a

temperate

or

atropical

region(D)

Comparisons

of

behavior

patterns

of

butterflies

andcertain

animal

groups9.

The

word

generated

in

line

26

is

closest

in

meaning

to(A)

requested(B)

caused(C)

assisted

(D)

estimated托福阅读答案：DABCC

CBCB托福阅读真题练习：海洋文化托福阅读文本：The

Native

American

peoples

of

the

north

Pacific

Coastcreated

a

highly

complex

maritime

culture

as

they

inventedmodes

of

production

unique

to

their

special

environment.

Inaddition

to

their

sophisticated

technical

culture,

they

alsoattained

one

of

the

most

complex

social

organizations

of

anynonagricultural

people

in

the

world.In

a

division

of

labor

similar

to

that

of

the

hunting

peoples

inthe

interior

and

among

foraging

peoples

throughout

theworld,

the

men

did

most

of

the

fishing,

and

the

womenprocessed

the

catch.Women

also

specialized

in

the

gathering

of

the

abundantshellfish

that

lived

closer

to

shore.

They

collected

oysters,crabs,

sea

urchins,

mussels,

abalone,

and

clams,

which

theycould

gather

while

remaining

close

to

their

children.

Themaritime

life

harvested

by

the

women

not

only

provided

food,but

also

supplied

more

of

the

raw

materials

for

making

toolsthan

did

fish

gathered

by

the

men.

Of

particular

importance

for

the

native

tool

kit

before

the

introduction

of

metal

was

thewide

knife

made

from

the

larger

mussel

shells,

and

a

variety

ofcutting

edges

that

could

be

made

from

other

marine

shells.The

women

used

their

tools

to

process

all

of

the

fish

andmarine

mammals

brought

in

by

the

men.

They

cleaned

the

fish,and

dried

vast

quantities

of

them

for

the

winter.

Theysun-dried

fish

when

practical,

but

in

the

rainy

climate

of

thecoastal

area

they

also

used

smokehouses

to

preserve

tons

offish

and

other

seafood

annually.

Each

product

had

its

ownpeculiar

characteristics

that

demanded

a

particular

way

ofcutting

or

drying

the

meat,

and

each

task

required

its

owncutting

blades

and

other

utensils.After

drying

the

fish,

the

women

pounded

some

of

them

intofish

meal,

which

was

an

easily

transported

food

used

in

soups,stews,

or

other

dishes

to

provide

protein

and

thickening

in

theabsence

of

fresh

fish

or

while

on

long

trips.

The

woman

alsomade

a

cheese-like

substance

from

a

mixture

of

fish

and

roeby

aging

it

in

storehouses

or

by

burying

it

in

wooden

boxes

orpits

lined

with

rocks

and

tree

leaves.托福阅读题目：1.

Which

aspect

of

the

lives

of

the

Native

Americans

of

thenorth

Pacific

Coast

does

the

passage

mainly

discuss?(A)

Methods

of

food

preservation(B)

How

diet

was

restricted

by

the

environment(C)

The

contributions

of

women

to

the

food

supply(D)

Difficulties

in

establishing

successful

farms2.

The

word

unique

in

line

2

is

closest

in

meaning

to(A)

comprehensible(B)

productive(C)

intentional(D)

particular3.

The

word

attained

in

line

3

is

closest

in

meaning

to(A)

achieved(B)

modified(C)

demanded(D)

spread4.

can

be

inferred

from

paragraph

1

that

the

socialorganization

of

many

agricultural

peoples

is(A)

more

complex

than

that

of

hunters

and

foragers(B)

less

efficient

than

that

of

hunters

and

foragers(C)

more

widespread

than

that

of

hunters

and

foragers(D)

better

documented

than

that

of

hunters

and

foragers5.According

to

the

passage

what

is

true

of

the

division

of

labor

mentioned

in

line

5?(A)

was

first

developed

by

NativeAmericans

of

the

northPacific

Coast.(B)

rarely

existed

among

hunting(C)

was

a

structure

that

the

Native

Americans

of

the

northPacific

Coast

shared

with

many

otherpeoples.(D)

provided

a

form

of

social

organization

that

was

foundmainly

among

coastal

peoples.6.

The

word

abundant

in

line

7

is

closest

in

meaning

to(A)

prosperous(B)

plentiful(C)

acceptable(D)

fundamental7.All

of

the

following

are

true

of

the

north

Pacific

coast

womenEXCEPT

that