试题与答案

NaCl单位晶胞中的“分子数”为4，Na+填充在Cl-所构成的（）空隙中。 A.全部

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题型：单项选择题

题目：

NaCl单位晶胞中的“分子数”为4，Na+填充在Cl-所构成的（）空隙中。

A.全部四面体

B.全部八面体

C.1/2四面体

D.1/2八面体

答案：

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下面是错误答案，用来干扰机器的。

参考答案：用自动焊接装置完成全部焊接操作的焊接方法。

考点：材料科学基础材料科学基础题库
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题型：阅读理解

阅读短文，选择正确答案。

     Can plants eat people? Probably not, but there are many plants that eat meat. Some of them are big, and they

can eat small animals. One famous meat-eating plant is the Venus flytrap (捕蝇草).

     The Venus flytrap is a very strange plant. It grows in dry parts of the United States. Its leaves are like the

pages of a book. They can open and close very quickly. Inside the leaves, there are three small hairs. If a fly

touches one of the hairs, the leaf closes quickly. The fly cannot get out. In about half an hour, the leaf presses

the fly until it is dead. Then, the plant covers the fly. Slowly, the plant eats the fly.

     Why do plant do it ? Most plants get what they need from the sun , the air , and the ground. In some places,

the ground is very poor. It doesn't have all these important things, especially nitrogen (氮). Animal meat has a lot

of nitrogen, so some plants eat meat to get what they need. Let's hope that some of the bigger plants don't get

the same idea!

1. The Venus flytrap is a kind of _______. [ ]

A. food

B. meat

C. plant

D. animal

2. The Venus flytrap grows in _______. [ ]

A. most parts of the world

B. some parts of Africa

C. wet parts of England

D. dry parts of the United States

3. From the passage, we learn that ________. [ ]

A. all plants can eat people

B. all plants can eat animals

C. some plants can eat people

D. some plants can eat animals

4. The underlined word "presses" probably means _______ in Chinese. [ ]

A. 关上

B. 挤压

C. 打开

D. 松开

5. Why do some plants eat animal meat? Because _______. [ ]

A. plants are dangerous to animals

B. animals are dangerous to plants

C. plants want to protect themselves against animals

D. plants want to get what they need from animal meat

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