高考英语复习语境20地球与宇宙奥秘探索课件

语境20地球与宇宙奥秘探索语境20地球与宇宙奥秘探索Ⅰ.阅读理解AThe

ocean

covers

approximately

70％

of

Earth’s

surface.

It’s

the

largest

livable

space

on

our

planet，

and

there’s

more

life

there

than

anywhere

else

on

Earth.

Through

exploration，

we’re

learning

more

about

its

biological，

chemical，

physical，

and

geological(地质的)

aspects.

Exploration

leads

to

discovery，

but

before

we

can

truly

explore，

we

must

map.Seafloor

mapping

provides

a

sense

of

what

may

lie

beneath

and

guides

decisions

about

where

to

explore.

While

the

entire

seafloor

has

been

mapped

using

data

collected

from

satellites，

these

data

provide

only

a

general

picture

of

what’s

there.

Detail

is

limited

on

these

maps，

so

some

important

geographical

features

like

seamounts

and

objects

like

shipwrecks(失事船只)

remain

unseen.As

of

2023，

24.9％

of

the

global

seafloor

had

been

mapped

with

modern

high－resolution(高分辨率的)

technology，

usually

fixed

on

ships，

which

can

reveal

the

seafloor

in

greater

detail.

While

almost

50％

of

the

seafloor

beneath

US

waters

had

been

mapped

to

these

modern

standards，

the

nation’s

seafloor

is

larger

than

the

land

area

of

all

50

states.

Thus，

there’s

still

a

significant

amount

of

seafloor

left

to

be

mapped

at

high

resolution.More

is

known

about

the

seafloor

than

the

species

that

call

the

ocean

home.

Seafloor

maps

can

provide

information

about

potential

habitats，

but

they

can’t

identify

species

on

the

seafloor

or

provide

information

about

how

they

interact

with

each

other

and

their

environments.

Scientists

estimate

there

may

be

between

700，000

and

1

million

species

in

the

ocean.

Roughly

two－thirds

of

these

species

have

yet

to

be

discovered

or

officially

described，

with

almost

2，000

new

species

accepted

by

the

scientific

community

each

year.We

have

a

great

deal

more

to

learn

about

our

ocean

and

what

lives

in

it，

but

progress

is

being

made.

We

learn

more

and

more

each

year.

But

the

ocean

will

never

be

fully

explored.

Earth

is

constantly

changing，

and

it’s

important

to

understand

these

changes

given

the

importance

of

the

ocean

in

our

everyday

lives.

【文章大意】

本文是一篇说明文。作者详细解释了海洋探索的重要性、海底测绘的现状、海洋生物的多样性以及我们对海洋及其生物的了解程度。文章通过提供数据、事实和科学估计来支持其观点，并强调了继续探索和研究海洋的必要性。1.

Why

is

seafloor

mapping

important

for

exploring

the

ocean？A.It

reveals

all

objects

on

the

seafloor.B.It

shows

the

seafloor

in

greater

detail.C.It

guides

decisions

about

where

to

sail.D.It

provides

a

general

picture

of

the

earth.解析：细节理解题。根据第二段“Seafloor

mapping

provides

a

sense

of

what

may

lie

beneath

and

guides

decisions

about

where

to

explore.

While

the

entire

seafloor

has

been

mapped

using

data

collected

from

satellites，

these

data

provide

only

a

general

picture

of

what’s

there.

Detail

is

limited

on

these

maps，

so

some

important

geographical

features

like

seamounts

and

objects

like

shipwrecks(失事船只)

remain

unseen.(海底测绘提供了一种可能在海底的感觉，并指导决定在哪里探索。虽然利用卫星收集的数据绘制了整个海底的地图，但这些数据只提供了那里的大致情况。这些地图上的细节有限，因此一些重要的地理特征，如海底山和沉船等物体仍然看不到。)”可知，海底测绘对于海洋探索很重要，卫星数据地图上有些细节看不到，海底测绘可以展示海底更详细的情况。故选B项。答案：B2.

Why

is

the

seafloor

beneath

US

waters

mentioned

in

Paragraph

3？A.To

stress

the

further

task

of

mapping

the

seafloor.B.To

explain

the

standards

of

mapping

the

seafloor.C.To

illustrate

the

geographical

features

of

the

seafloor.D.To

highlight

the

significance

of

mapping

the

seafloor.解析：推理判断题。根据第三段中的“While

almost

50％

of

the

seafloor

beneath

US

waters

had

been

mapped

to

these

modern

standards，

the

nation’s

seafloor

is

larger

than

the

land

area

of

all

50

states.

Thus，

there’s

still

a

significant

amount

of

seafloor

left

to

be

mapped

at

high

resolution.(虽然美国水域下近50％的海底已经按照这些现代标准绘制了地图，但美国的海底面积比所有50个州的陆地面积都要大。因此，仍有大量的海底有待以高分辨率绘制。)”可知，第三段提到美国水域下方的海底是为了强调绘制海底地图的进一步任务还很艰巨。故选A项。答案：A3.

What

can

we

learn

from

the

seafloor

maps？A.The

quality

of

the

water.B.The

environment

of

ocean.C.The

homes

of

sea

species.D.The

endangered

sea

species.解析：细节理解题。根据第四段中的“More

is

known

about

the

seafloor

than

the

species

that

call

the

ocean

home.

Seafloor

maps

can

provide

information

about

potential

habitats，

but

they

can’t

identify

species

on

the

seafloor

or

provide

information

about

how

they

interact

with

each

other

and

their

environments.(人们对海底的了解比以海洋为家的物种还要多。海底地图可以提供关于潜在栖息地的信息，但它们不能识别海底的物种，也不能提供关于它们如何相互作用以及它们的环境的信息。)”可知，通过海底地图我们可以了解海洋物种的栖息地。故选C项。答案：C4.

What

is

the

best

title

of

the

text？A.How

Can

the

Seafloor

Be

Mapped？B.What

Species

Are

Living

in

the

Ocean？C.Why

Is

It

Important

to

Exploit

the

Ocean？D.How

Much

of

the

Ocean

Has

Been

Explored？解析：标题归纳题。通读全文，尤其是根据第二段中的“Seafloor

mapping

provides

a

sense

of

what

may

lie

beneath

and

guides

decisions

about

where

to

explore.(海底测绘提供了一种可能在海底的感觉，并指导决定在哪里探索。)”第三段“As

of

2023，

24.9％

of

the

global

seafloor

had

been

mapped

with

modern

high－resolution(高分辨率的)

technology，

usually

fixed

on

ships，

which

can

reveal

the

seafloor

in

greater

detail.

While

almost

50％

of

the

seafloor

beneath

US

waters

had

been

mapped

to

these

modern

standards，

the

nation’s

seafloor

is

larger

than

the

land

area

of

all

50

states.

Thus，

there’s

still

a

significant

amount

of

seafloor

left

to

be

mapped

at

high

resolution.(截至2023年，全球24.9％的海底已经用现代高分辨率技术绘制了地图，这些技术通常固定在船上，可以更详细地显示海底。虽然美国水域下近50％的海底已经按照这些现代标准绘制了地图，但美国的海底面积比所有50个州的陆地面积都要大。因此，仍有大量的海底有待以高分辨率绘制。)”以及最后一段“We

have

a

great

deal

more

to

learn

about

our

ocean

and

what

lives

in

it，

but

progress

is

being

made.

We

learn

more

and

more

each

year.

But

the

ocean

will

never

be

fully

explored.

Earth

is

constantly

changing，

and

it’s

important

to

understand

these

changes

given

the

importance

of

the

ocean

in

our

everyday

lives.(关于海洋和海洋中的生物，我们还有很多需要了解的，但我们正在取得进展。我们每年都学得越来越多。但海洋永远不会被完全探索。地球在不断变化，鉴于海洋在我们日常生活中的重要性，了解这些变化非常重要。)”可知，作者详细解释了海洋探索的重要性、海底测绘的现状、海洋生物的多样性以及我们对海洋及其生物的了解程度。文章通过提供数据、事实和科学估计来支持其观点，并强调了继续探索和研究海洋的必要性。D项“How

Much

of

the

Ocean

Has

Been

Explored？(有多少海洋已经被勘探过了？)”最适合作文章标题。故选D项。答案：DBMuch

of

Earth

is

unexplored.

An

ocean

census(普查)

hopes

to

change

that.“Earth”

has

always

been

an

odd

choice

of

name

for

the

third

planet

from

the

Sun.

After

all，

two－thirds

of

its

surface

is

covered

not

by

earth

at

all，

but

by

oceans

of

water.Because

humans

are

land

animals，

most

of

the

Earth

remains

under－explored.

Marine(海洋的)

biologists

think

the

oceans

might

host

more

than

2

million

species

of

marine

animals，

of

which

they

have

so

far

identified

perhaps

a

tenth.A

new

initiative

hopes

to

change

this.

Launched

in

London

on

April

27th，

Ocean

Census

aims

to

discover

100，000

new

species

of

marine

animal

over

the

coming

decade.

It

is

backed

by

Nekton，

a

British

marine－research

institute，

and

the

Nippon

foundation，

Japan’s

biggest

charitable

foundation.

Its

first

ship，

the

Norwegian

icebreaker

Kronprins

Haakon，

set

sail

on

April

29th，

bound

for

the

Barents

Sea.The

initiative

is

happening

for

two

reasons.

One

is

that

the

longer

scientists

wait，

the

less

there

will

be

to

identify.

Climate

change

is

heating

the

oceans，

as

well

as

making

them

more

acidic(酸的)

as

carbon

dioxide

dissolves

goes

into

the

water.

Already

around

half

the

world’s

coral

reefs(珊瑚)－thought

to

be

home

to

around

25％

of

all

ocean

species－have

been

lost.

Oliver

Steeds，

Nekton’s

founder，

says

that

one

of

Ocean

Census’s

priorities

will

be

identifying

species

thought

to

be

in

the

greatest

danger

from

climate

change.

The

second

reason

is

technological.

Marine

biologists

find

about

2，000

new

species

a

year，

a

rate

hardly

changed

since

Darwin’s

day.

Ocean

Census

is

betting

it

can

go

faster.Exactly

what

the

new

effort

might

turn

up

is

impossible

to

predict.

But

history

suggests

it

will

be

fruitful.

Half

a

century

ago

scientists

discovered

hot

vents(喷口)

on

the

sea

bed.

These

days，

such

vents

are

one

possible

candidate

for

the

origin

of

all

life

on

Earth.

There

are

more

practical

benefits，

too.

Many

drugs，

for

example，

come

originally

from

biological

substance.

An

ocean

full

of

unidentified

life

will

almost

certainly

prove

a

rich

mine

from

which

to

mine

more.

【文章大意】

本文是一篇说明文。文章主要说明了科学家倡议进行海洋普查来深入了解地球，并解释了这一举措背后的原因。5.

Why

is

“Earth”

an

odd

choice

of

name

for

the

third

planet

from

the

Sun？A.Its

climate

is

changing

rapidly.B.Humans

have

not

explored

much

of

it.C.Most

of

its

surface

is

covered

by

water.D.It

hosts

a

large

number

of

marine

animals.解析：细节理解题。根据第二段“'Earth'

has

always

been

an

odd

choice

of

name

for

the

third

planet

from

the

Sun.

After

all，

two－thirds

of

its

surface

is

covered

not

by

earth

at

all，

but

by

oceans

of

water.(用”地球“来命名这颗距太阳第三远的行星一直是个奇怪的选择。毕竟，它三分之二的表面根本不是被陆地覆盖，而是被海洋覆盖。)”可知，用“地球”这个名字来称呼离太阳第三远的行星是一个奇怪的选择，是因为它的大部分表面被水覆盖。故选C。答案：C6.

What

can

we

infer

from

Paragraph

5？A.The

rate

of

discovering

new

species

won’t

change.B.The

new

initiative

will

mainly

focus

on

coral

reefs.C.Climate

change

has

a

great

impact

on

marine

species.D.Scientists

have

identified

nearly

all

the

species

in

the

ocean.解析：推理判断题。根据第五段中的“The

initiative

is

happening

for

two

reasons.

One

is

that

the

longer

scientists

wait，

the

less

there

will

be

to

identify.

Climate

change

is

heating

the

oceans，

as

well

as

making

them

more

acidic(酸的)

as

carbon

dioxide

dissolves

goes

into

the

water.

Already

around

half

the

world’s

coral

reefs(珊瑚)－thought

to

be

home

to

around

25％

of

all

ocean

species－have

been

lost.

Oliver

Steeds，

Nekton’s

founder，

says

that

one

of

Ocean

Census’s

priorities

will

be

identifying

species

thought

to

be

in

the

greatest

danger

from

climate

change.(这一举措的出现有两个原因。一个是，科学家等待的时间越长，能确定的就越少。气候变化正在加热海洋，同时随着二氧化碳溶解到水中，海洋变得更酸。世界上大约一半的珊瑚礁——被认为是25％海洋物种的家园——已经消失了。Nekton的创始人Oliver

Steeds说，海洋普查的首要任务之一将是确定那些被认为受到气候变化威胁最大的物种。)”可推知，气候变化对海洋物种有很大的影响。故选C。答案：C7.

What

might

be

the

potential

benefits

of

the

Ocean

Census

according

to

the

last

paragraph？A.It

may

result

in

a

reduction

in

overfishing.B.It

may

lead

to

the

discovery

of

new

drugs.C.It

may

contribute

to

the

advancement

of

technology.D.It

may

prove

the

oceans

are

our

life－support

system.解析：细节理解题。根据最后一段中的“Many

drugs，

for

example，

come

originally

from

biological

substance.

An

ocean

full

of

unidentified

life

will

almost

certainly

prove

a

rich

mine

from

which

to

mine

more.(例如，许多药物最初来自生物物质。一个充满未知生命的海洋几乎肯定是一个丰富的矿藏，我们可以从中开采更多矿。)”可知，海洋普查的潜在好处是可能导致新药的发现。故选B。答案：B8.

What’s

the

best

title

for

the

text？A.The

Endangered

PlanetB.Reducing

Sea

Pollution：

A

Global

InitiativeC.How

to

Protect

the

Oceans？D.The

Misnamed

Earth：

Exploring

the

Ocean’s

Secrets答案：D解析：标题归纳题。根据第一段“Much

of

Earth

is

unexplored.

An

ocean

census(普查)

hopes

to

change

that.(地球上的许多地方还没有被探索过。一项海洋普查希望改变这种状况。)”并结合文章主要说明了科学家倡议进行海洋普查来深入了解地球，并解释了这一举措背后的原因可知，D项“错误命名的地球：探索海洋的秘密”最适合作文章标题。故选D。Ⅱ.完形填空Growing

up

in

Mauritius，

I

love

nature.

Behind

my

house，

there

is

a

mountain

named

Le

Pouce，

where

I

spent

much

time

1

the

forest

as

a

kid.

However，

my

instinct

(天性)

for

exploration

stopped

at

the

water’s

edge.

Even

though

Mauritius

is

an

island

country

2

by

the

Indian

Ocean，

the

thought

of

entering

the

ocean

made

me

scared.When

I

was

about

10，

this

started

to

3

.

I

began

learning

about

the

threat

climate

change

presented

to

island

countries，

and

I

started

4

an

interest

in

protecting

the

environment.

I

watched

nature

documentaries，

5

the

steps

I

could

take

to

change

the

world，

yet

I

still

didn’t

know

how

to

effectively

achieve

it.

Later，

I

took

the

National

Geographic

Society’s

Exploring

Conservation

courses，

which

set

me

on

a

path

to

helping

start

and

6

，

The

Oceanic

Project，

an

organization

dedicated

to

helping

people

understand

the

ocean

and

enhancing

people’s

7

of

protecting

the

ocean.Gradually，

I

realized

how

much

humans

8

the

ocean

for

its

natural

resources

and

that

it

was

not

as

dangerous

as

I

had

imagined.

My

fear

was

rooted

in

a(n)

9

of

falling

into

a

river

in

my

childhood.

Determined

to

10

it，

I

became

a

certified

diver

last

year.Diving

plays

a

big

part

in

my

life

now，

and

I

work

to

11

the

protection

of

the

underwater

environment.

I

helped

run

a

summer

camp

for

young

divers.

During

that

time，

I

led

a

beach

cleanup

to

help

the

participants

understand

how

human

litter

could

end

up

in

the

ocean.

I

got

encouraged

by

the

12

of

the

activity

when

a

parent

told

me

her

son

insisted

on

13

plastic

items

in

their

home

with

bamboo

alternatives

after

returning

home.Protecting

the

ocean

is

very

14

and

I’ll

keep

dedicating

myself

to

it.

And

I

15

hope

more

people

will

join

me.

Only

with

everyone’s

effort

can

we

make

the

world

a

wonderful

place

for

human

beings.

【文章大意】

本文是一篇记叙文。文章主要讲述了作者小时候害怕大海，后来通过学习开始了解到保护海洋环境的重要性，并成立组织，领导和组织保护海洋环境的活动，同时呼吁大家加入自己的行列，希望通过每个人的努力来使世界变得更加美好。1.

A.exploringB.transforming

C.extendingD.constructing答案：A解析：考查动词词义辨析。句意：在我的房子后面，有一座叫Le

Pouce的山，我小时候经常在那里探索森林。A.exploring探索；B.transforming使转变；C.extending延长；D.constructing建造。根据下文“However，

my

instinct

(天性)

for

exploration”可知是原词复现，表示探索森林。故选A。2.

A.ruinedB.surrounded

C.coveredD.represented答案：B解析：考查动词词义辨析。句意：虽然毛里求斯是一个被印度洋包围的岛国，但一想到要进入海洋，我就感到害怕。A.ruined毁坏；B.surrounded包围；C.covered覆盖；D.represented代表。根据上文“an

island

country”和常识可知，毛里求斯是一个被印度洋包围的岛国。故选B。3.

A.changeB.worsen

C.repeatD.occur答案：A解析：考查动词词义辨析。句意：当我大约10岁的时候，这种情况开始改变。A.change改变；B.worsen变得更坏；C.repeat复述；D.occur发生。下文“I

began

learning

about

the

threat

climate

change

presented

to

island

countries，

and

I

started

4

an

interest

in

protecting

the

environment.”提到作者由“探索的本能停止在水边”到“开始了解岛国的环境问题”，可知是改变。故选A。解析：考查动词词义辨析。句意：当我大约10岁的时候，这种情况开始改变。A.change改变；B.worsen变得更坏；C.repeat复述；D.occur发生。下文“I

began

learning

about

the

threat

climate

change

presented

to

island

countries，

and

I

started

4

an

interest

in

protecting

the

environment.”提到作者由“探索的本能停止在水边”到“开始了解岛国的环境问题”，可知是改变。故选A。4.

A.providingB.hiding

C.developingD.resisting答案：C解析：考查动词词义辨析。句意：我开始了解到气候变化给岛国带来的威胁，我开始对保护环境产生兴趣。A.providing提供；B.hiding隐藏；C.developing产生；D.resisting抵制。根据上文“I

began

learning

about

the

threat

climate

change

presented

to

island

countries”可知，作者开始了解岛国的气候变化带来的威胁，所以是对保护环境产生兴趣。故选C。5.

A.avoidingB.teaching

C.pretendingD.considering答案：D解析：考查动词词义辨析。句意：我看自然纪录片，考虑我可以采取哪些措施来改变世界，但我仍然不知道如何有效地实现它。A.avoiding避免；B.teaching教；C.pretending假装；D.considering考虑。根据下文“the

steps

I

could

take

to

change

the

world”可知，是思考采取什么样的措施来改变世界。故选D。6.

A.leadB.follow

C.recognizeD.prevent答案：A解析：考查动词词义辨析。句意：后来，我参加了国家地理学会的探索保护课程，这使我走上了帮助启动和领导海洋项目的道路，这是一个致力于帮助人们了解海洋、提高人们保护海洋意识的组织。A.lead领导；B.follow跟随；C.recognize认出；D.prevent阻止。根据下文“The

Oceanic

Project，

an

organization

dedicated

to

helping

people

understand

the

ocean”可知，是启动和领导一个组织。故选A。7.

A.hesitationB.awareness

C.memoryD.guess答案：B解析：考查名词词义辨析。句意同上题。A.hesitation犹豫；B.awareness意识；C.memory记忆；D.guess猜测。根据下文“of

protecting

the

ocean”可知，是提高人们保护海洋的意识。故选B。8.

A.paid

backB.adapted

to

C.depended

onD.kept

up答案：C解析：考查动词短语辨析。句意：渐渐地，我意识到人类是多么依赖海洋的自然资源，海洋并没有我想象的那么危险。A.paid

back偿还；B.adapted

to适应；C.depended

on依靠；D.kept

up保持。根据本句“how

much

humans

8

the

ocean

for

its

natural

resources”和常识可知，是人类依赖海洋提供的自然资源。故选C。解析：考查动词短语辨析。句意：渐渐地，我意识到人类是多么依赖海洋的自然资源，海洋并没有我想象的那么危险。A.paid

back偿还；B.

adapted

to适应；C.depended

on依靠；D.kept

up保持。根据本句“how

much

humans

8

the

ocean

for

its

natural

resources”和常识可知，是人类依赖海洋提供的自然资源。故选C。9.

A.moodB.skill

C.hobbyD.experience答案：D解析：考查名词词义辨析。句意：我的恐惧源于我童年时掉进河里的一次经历。A.mood心情；B.skill技能；C.hobby爱好；D.experience经历。根据下文“falling

into

a

river

in

my

childhood”可知，是童年的一次经历让作者害怕水。故选D。10.

A.confirmB.neglect

C.overcomeD.analyze答案：C解析：考查动词词义辨析。句意：我决心克服它，去年成为了一名合格的潜水员。A.confirm确认；B.neglect忽略；C.overcome克服；D.analyze分析。根据上文可知，作者因为童年掉进河里的经历害怕水以及下文“I

became

a

certified

diver

last

year”可知，作者决定克服这种恐惧。故选C。11.

A.turn

downB.hold

back

C.add

upD.contribute

to答案：D解析：考查动词短语辨析。句意：现在潜水在我的生活中占据了很大的一部分，我的工作是为保护水下环境作出贡献。A.turn

down关小；B.hold

back阻碍；C.add

up总计；D.contribute

to贡献。根据下文“the

protection

of

the

underwater

environment”和作者成立组织可知，都是为了保护海洋环境，所以作者的工作是为保护水下环境作出贡献。故选D。12.

A.introductionB.influence

C.advertisementD.prediction答案：B解析：考查名词词义辨析。句意：当一位家长告诉我，她的儿子回家后坚持用竹子代替家里的塑料物品时，我受到了鼓舞，因为活动起了作用。A.introduction介绍；B.influence作用；C.advertisement广告；D.prediction预测。根据下文“when

a

parent

told

me

her

son

insisted

on

13

plastic

items

in

their

home

with

bamboo

alternatives

after

returning

home”可知，活动起到了作用，改变了孩子的行为，作者因此受到鼓舞。故选B。解析：考查名词词义辨析。句意：当一位家长告诉我，她的儿子回家后坚持用竹子代替家里的塑料物品时，我受到了鼓舞，因为活动起了作用。A.introduction介绍；B.influence作用；C.advertisement广告；D.

prediction预测。根据下文“when

a

parent

told

me

her

son

insisted

on

13

plastic

items

in

their

home

with

bamboo

alternatives

after

returning

home”可知，活动起到了作用，改变了孩子的行为，作者因此受到鼓舞。故选B。13.

A.mixingB.burning

C.replacingD.combining答案：C解析：考查动词词义辨析。句意同上题。A.mixing混合；B.burning燃烧；C.replacing代替；D.combining结合。根据下文“plastic

items

in

their

home

with

bamboo

alternatives

after

returning

home”可知，是用竹子代替家里的塑料物品。故选C。14.

A.riskyB.impractical

C.shockingD.crucial答案：D解析：考查形容词词义辨析。句意：保护海洋是非常重要的，我将继续致力于它。A.risky冒险的；B.impractical不现实的；C.shocking令人震惊的；D.crucial至关重要的。根据上文描述和下文“I’ll

keep

dedicating

myself

to

it”可知，海洋提供人类依赖的自然资源，所以作者认为保护海洋是重要的，并且会继续下去。故选D。15.

A.sincerelyB.suddenly

C.formallyD.seemingly答案：A解析：考查副词词义辨析。句意：我真诚地希望更多的人能加入我的行列。A.sincerely真诚地；B.suddenly突然地；C.formally正式地；D.seemingly看起来似乎。根据上文可知，作者说保护海洋环境很重要，所以他真诚地希望更多的人加入自己的队伍。故选A。Ⅲ.语法填空China

has

been

pushing

space

exploration

boundaries

on

its

own

over

the

past

three

decades.

It

embarked

on(开始)

a

“three－step”

strategy

1.

(boost)

its

human

space

program

in

1992

when

2.

(construct)

a

manned

orbiting

laboratory

was

still

a

flight

of

fancy

for

the

Chinese

people.The

first

step

was

to

send

astronauts

into

space

3.

ensure

their

safe

return.

The

second

step

was

to

develop

advance