问题 问答题 简答题

什么叫必需氨基酸?什么叫氨基酸的互补作用?

答案

参考答案:

必需氨基酸是指在动物体内不能合成,或合成速度和数量不能满足动物正常生命活动的需要,必须由饲料中供给的氨基酸。氨基酸的互补作用是指由于各种饲料所含氨基酸的种类及数量差异很大,在配合饲料时将两种或两种以上饲料混合使用,以达到取长补短之功效及提高其营养价值。

阅读理解

One day an American called Simon went to London to visit his friend, Rick. Rick told him that his flat was on the first floor. When he arrived, Simon went straight to the first floor of the building. But he was told that there was no Rick on that floor. Do you know why?

In fact, the British call the first floor of a building the ground floor. The floor above the ground floor is the first floor, which Americans would call the second floor.

The story shows that there are a few culture differences between Britain and American, though the British and Americans both speak English.

The British usually hide their feelings. They seldom start a conversation with strangers. For example, on the train the British often spend their time reading newspapers or books. But Americans are quite different. They’re more active and easier to talk with.

The British and Americans may use different terms for many things. The British usually use football ,eraser and mail while Americans prefer to soccer, rubber and post.

小题1: Simon went to London to         .

A. spend his holiday B. visit his friend C. study English

小题2:Which picture shows us where Rick’s flat was?

小题3:According to the passage, the British usually spend their time        on the train.

A. playing cards B. talking loudly   C. doing some reading

小题4:What does the underlined word “terms” mean in Chinese in the passage?

A. 成果   B.术语 C. 学期

小题5:What’s the main idea of the passage?

A. Different culture between Britain and America.

B. The British and Americans have the same language.

C. The British and Americans have different words.

单项选择题