题干

某班48名同学进行有关“耳垂遗传”的模拟活动。老师告诉大家,耳垂有无是一对相对性状,决定有耳垂的基因(A)是显性基因,决定无耳垂的基因(a)是隐性基因。

老师为每个学习小组准备了蓝色、红色卡片各两张,其中蓝色卡片代表父亲,红色卡片代表母亲。两张蓝色卡片上分别写有A、a,两张红色卡片也分别写有A、a。然后,让每个同学随机抽取一张蓝色卡片和一张红色卡片进行组合。请回答下列问题:

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根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,并在答题卡上将该项涂黑。选项中有两项为多余选项。

      Sleep is something we all do. But some people need to sleep more than others. Babies sleep most of the time. Children in school sleep about ten to twelve hours a night. Most adults sleep only seven or eight hours.____All parts of our bodies have to rest after they work.. Our arms need a rest after we lift heavy thing, When we run fast, our legs work hard. They get tired. We have to rest them. Our brains workhard, too.____ We can sit quite still and rest our arms andlegs. But our brains aren't resting. They go right on thinking as long as weare awake.

      Our brains slow down a bit when we sleep and dream.____ Instead of thinking wide-awake thoughts, our brains make up dreams. Some dreams are very pleasing. Some are not. Most of thetime we forget them when we wake up.

      Scientists have tried to find out what would happen if people were not allowed to sleep. They asked some people not to go to bed. The people stayed up all night and all the next day. They stayed up the next night too,and the day after. They played games, but they made mistakes. They forgot things.____ The people grew rude and mean. They became angry with their friends. Finally they were too tired to stand up. When they sat down, they fell asleep.

      Scientists have found that if people are not allowed to sleep and to dream, they act in an unusual way.____But we do know that we need it to stay well. So tonight have a goodsleep. Lie down under the covers. Shut your eyes. Let your thoughts wander.Soon you’ll stop thinking. You'll be asleep.

A. It was hard for their tired brains to work.

B. When we are awake, they help us pay attention to the worldaround us

C. But babies, children, and adults----all of us need to haveour sleep

D. Good sleep helps to improve one's memory

E. No one knows why sleep is so good for us

F. But even as we sleep our brains are doing some work

G. Of course you will have a good sleep