用NA表示阿伏加德罗常数,以下说法正确的是 [ ] A.1 mol乙烷中的氢原子

题型:选择题

问题:

用NA表示阿伏加德罗常数,以下说法正确的是

[     ]

A.1 mol乙烷中的氢原子被氯原子完全取代,需要氯气分子数为 4 NA

B.1 mol的NO2 与水完全反应转移电子数为NA

C.在标准状况下2.24 L O2 和3.2 g O3含有氧原子都为0.2 NA .

D.在标准状况下2.24 L丙烷和戊烷混合物含分子个数为0.1 NA.

考点:阿伏加德罗常数
题型:选择题

雷电电性质的破坏作用主要包括( )。

A.破坏高压输电系统,毁坏电气设备的绝缘,烧断电线或劈裂电杆,造成大规模停电事故

B.可能引起短路,导致火灾或爆炸事故

C.雷击产生的静电场突变和电磁辐射干扰电视电话通信,甚至使通信中断

D.巨大的雷电流通过导体能够烧毁导体

E.直击雷放电的高温电弧能直接引燃邻近的可燃物

题型:选择题

第三部分:阅读理解(共20小题,满分40分)

Many Chinese students who have learnt English for more than ten years are still unable to speak English very well when they meet a foreigner. They seem to have mastered the basic language structure, but a conversation in English will make them feel uneasy. They are afraid that other people might find out their mistakes.

It's unusual that many students who are bad speakers of English can write English perfectly. This proves that they are unable to organize their idea in English. The center of the problem is that they lack practice and confidence.

Why should you be afraid? Do you fear those foreigners with whom you are speaking? Don't be shy, they will not laugh at you just for a little mistake you make. The best way to get rid of trouble is to learn to speak by speaking more. I am sure that constant(经常的) practice will help you succeed.

56. What's the best title for the passage?

A. How to Speak to Foreigners          B. How to Study English Well

C. How to Organize the Idea in English   D. Practise Speaking English All the Time

57. Many Chinese students can write English very well, but they cannot speak English fluently because ________

A. they seldom meet foreigners    B. they seldom practise speaking English

C. they had no chance to speak English

D. they think it's enough to master the basic language structure only

58. So many Chinese students are afraid of speaking to foreigners because _____.

A. they are afraid they can't understand foreigners

B. they don't think their English is poor

C. they worry about making mistakes in their speaking

D. they didn't like speaking to foreigners

59. According to the passage, which of the following is NOT true?

A. We can speak English fluently by doing more speaking.

B. If you can write English perfectly, you are able to organize your idea in English.

C. If you can write good English composition, you can speak English very well.

D. Any Chinese students can't speak English fluently because they are afraid of making mistakes.

60. In the last paragraph, the expression "get rid of" means_______.

A. throw away     B. free oneself from     C. give up     D. do with

题型:选择题

下列关于监理大纲、监理规划和监理实施细则之间关系的表述中,正确的是()。

A.监理大纲的内容比监理规划的内容更全面、更翔实

B.监理实施细则应在监理规划的基础上进行编写

C.监理大纲应按监理规划的有关内容编写

D.三者编写顺序为监理规划、监理大纲和监理实施细则

题型:选择题

什么管理,是一种以走动管理为主的直接亲近员工的开放式的有效管理?

题型:选择题

下列方程中不是静止流体平衡方程式的是()。

A、p2=p1+(z1-z2)ρg

B、p2=p0+hρg

C、p=p0+hρg

更多题库