问题 选择题

将植物栽培在适宜的光照、温度和充足的CO2条件下,如果在2h时,将环境中某一条件改变,此时,叶肉细胞中的C3、C5、ATP含量变化如图:那么改变的条件是

[ ]

A.加强光照

B.降低CO2浓度

C.提高CO2浓度

D.降低温度

答案

答案:A

阅读理解

阅读理解。

     How words came into being is unknown. All we assume (推测) is that some early men invented certain

sounds, in one way or another, to express thoughts and feelings, actions and things, so that they could talk

with each other. Later they agreed upon certain signs, called letters, which could be put together to show

those sounds, and which could be written down. Those sounds, whether spoken or written in letters, are

called words.

     The power of words, then, lies in their associations-the thing they bring up to minds. Words become

filled with meaning for us by experience; and the longer we live, the more certain words bring back to us the

happy and sad events of our past; and the more we read and learn, the more the number of words that means

something to us increases.

     Great writers are those who not only have great thoughts but also express these thoughts in words which

have powerful effects on our minds and feelings. This clever use of words is what we call literary style (文

体). Above all, the real poet is a master of words. He can express his meaning in words which sing like music,

and which by their position and association can move men to tears. We should therefore learn to choose our

words carefully and use them correctly, or they will make our speech silly and common.

1. We learn from the text that language might have begun with _____. [ ]

A. expressions

B. actions

C. signs

D. sounds

2. What is mainly discussed in Paragraph 2? [ ]

A. The meaning of new words.

B. The relation of human experience with words.

C. The importance of old words.

D. The gradual change and development of words.

3. In the last paragraph, what does the author suggest that we should do? [ ]

A. Use words skillfully.

B. Make musical speeches.

C. Learn poems by heart.

D. Associate with listeners.

单项选择题