A short sleep in the deep

主題語境：動物睡眠 篇幅：359詞 建議用時：7分鐘

1If you've ever seen elephant seals lying on a beach,you might think all they do is sleep.But scientists have discovered that when elephant seals are in the ocean,they hardly sleep at all.On average,elephant seals sleep just two hours a day.

2Elephant seals spend most of their time in the ocean.For about seven months of the year,they are in the water constantly.Even though elephant seals are large animals,they have to be careful in the ocean.Near the surface,predators like sharks are a constant danger.Elephant seals spend most of their time diving deep underwater,looking for food.They can dive as deep as 750 meters below the surface,and can hold their breath for over an hour.Usually,they will dive for about 30 minutes,and then come up for air for just a couple of minutes before diving again.

3Animals like dolphins and sea lions have a special trick.One half of their brain can sleep,while the other stays awake.But elephant seals are like humans—both halves of the brain need to go to sleep at the same time.So how do they sleep? To find out,a scientist named Jessica Kendall-Bar created a special cap that could record the elephant seals'brain activity.The cap also collected information on the elephant seals' heart rates,how their bodies were moving,and how deep they were.Dr Kendall-Bar and her team put the caps on thirteen young female elephant seals.

4The scientists learned that elephant seals only sleep for about 10 minutes at a time in the ocean.As they began to sleep,the elephant seals could control their bodies,gliding down smoothly.But when they were deeply asleep,they simply began to fall,spinning in a circle“l(fā)ike a falling leaf”.

5Using the information they gathered from the cap-wearing elephant seals,the scientists created a computer program to study older records of elephant seals trips.The scientists found that elephant seals only sleep for about two hours a day when they're in the ocean.Back on land,they sleep for about 10.8 hours a day.

Reading

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Detail 1.How deep can elephant seals dive below the surface?

A.As deep as 750 meters.

B.As deep as 70 meters.

C.As deep as 30 meters.

D.As deep as 13 meters.

Detail 2.Why did Jessica create the special cap?

A.To find out how dolphins dive.

B.To find out how elephant seals sleep.

C.To record animals'activities under the sea.

D.To record some tricks of sea lions.

Gist 3.What does paragraph 4 focus on?

A.A falling leaf.

B.A computer program.

C.The findings of a study.

D.The caps on elephant seals.

Inference 4.What can be inferred about elephant seals from paragraph 5?

A.One half of their brain can sleep.

B.They sleep longer on land than in the ocean.

C.Both halves of their brain need sleep.

D.They enjoy their trips on land.

Language

Study

I.日積月累

constantlyadv.不斷地

predatorn.捕食性動物

spendv.花費

divev.潛水

usuallyadv.通常

capn.帽子

femaleadj.雌性的；女性的

glidev.滑翔

smoothlyadv.平滑地；流暢地

spinv.旋轉(zhuǎn)

on average 平均

hold one's breath 屏息

Ⅱ.單句填空

1.She spent￡100________a new dress.

2.How long does the journey________(usual)take?

3.As elephant seals began to sleep,they could control their bodies,________(glide)down smoothly.

4.Fashion is________(constant)changing.

5.Four hundred people a year die of this disease________average.