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

题型:单项选择题

问题:

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

考点:材料科学基础材料科学基础题库
题型:单项选择题

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

题型:单项选择题

下列不属于自动喷水灭火系统水压试验条件的是()。

A.环境温度不低于5℃

B.系统设计工作压力不大于1.0MPA的,水压强度试验压力为设计工作压力的1.5倍,且不低于1.4MPA

C.水压严密性试验压力为系统设计工作压力

D.水压强度试验的测试点设在系统管网的最低点

题型:单项选择题

项目自我总结评价与项目后评价基本一致,区别在于前者是站在( )角度进行总结,后者是站第三者角度对项目进行分析。

A.业主

B.决策者

C.投资者

D.承包商

题型:单项选择题

在因素比较法中所选择的标杆职位数量一般为()个。

A、10~15

B、15~30

C、15~20

D、30~40

题型:单项选择题

手少阴心经的第一个腧穴是()

A.天泉

B.水泉

C.极泉

D.廉泉

E.曲泉

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