下列关于石油中的含氮化合物加氢脱氮反应的共同特点是()。A、氮杂环首先加氢饱和,然后

题型:多项选择题

问题:

下列关于石油中的含氮化合物加氢脱氮反应的共同特点是()。

A、氮杂环首先加氢饱和,然后C-N键发生氢解反应生成胺类,最后再加氢脱氮生成烃类和氨

B、加氢脱氮总反应速率的控制因素是加氢饱和反应的化学平衡

C、和脱硫一样,有直接氢解和先加氢再氢解两条路线

D、和脱芳一样,受到热力学限制

考点:汽油加氢装置操作工考试汽油加氢装置操作工(技师)汽油加氢装置操作工(技师)题库
题型:多项选择题

阅读理解。

     Can you swim? Do you like swimming? Yes? Well, how can you learn to swim? I think the best way is

to go into the water and learn. I'm afraid you'll never learn to swim just by reading books about swimming

or looking at others swimming. It's the same with the English study. We must practice, practice and practice.

     Listening and speaking are very important for beginners. The children in English-speaking countries first

listen to others. Then they try to imitate and speak. We can listen to English programs on radio. You may just

understand a few words. It doesn't matter. Just be relaxed, try to catch every word. Somebody may be a

good listener. But he dare not speak. He's afraid of making mistakes. You know we sometimes make mistakes

when we speak Chinese. Don't be afraid. We must be brave. If you really want to learn English well, you must

try to speak with everyone as long as he knows English. Whether you know him or not is not important, when

there's nobody to talk with, you can talk to yourself in English. It's interesting and also a good way to practice

your spoken English. Remember, the more you speak, the fewer mistakes you'll make.

     Reading and writing are more important for senior school students. First we must choose the books we're

interested in. A lot of reading will improve your language sense. This is the most important.

     Keep writing English diaries. We can also write English articles. You may even post them to English

magazines. Don't be afraid of failure. Failure is the mother of success.

     Easier said than done. Well, let's do more practice from now on. I'm sure you'll learn English well in this

way.

1. You can learn to swim by _____. [ ]

A. reading books about it

B. looking at others swimming

C. having lessons on it

D. going into the river and learning

2. We should learn English by _____. [ ]

A. listening and speaking

B. reading and writing

C. both A and B

D. swimming

3. What will you do with mistakes when you speak? [ ]

A. Don't make mistakes.

B. Study hard.

C. Try not to speak English.

D. Don't be afraid.

4. What's more important for senior school students? [ ]

A. listening

B. speaking

C. reading and writing

D. learning

5. We can listen to English _____, according to the passage.[ ]

A. by train

B. on the radio

C. every minute

D. now and then

题型:多项选择题

电子的发现说明原子是可分的,原子是由______ 和______组成的,原子核由______ 和______组成.

题型:多项选择题

为了探究蜡烛燃烧的现象,做了下表中的实验,请你帮忙完成实验报告的内容:

实验步骤实验现象结 论
点燃蜡烛,将一根火柴横在火焰上方片刻;火柴梗的______(填“a”、“b”或“c”)处最先碳化.蜡烛火焰的______温度最高.
将一只干冷的烧杯罩在火焰上方;烧杯内壁出现水雾.说明蜡烛燃烧生成了______.
将一只内壁附有澄清石灰水的烧杯罩在火焰上方.烧杯内壁有白色固体生成说明蜡烛燃烧还生成______.

蜡烛燃烧的文字表达式为:

______.

题型:多项选择题

合金钢中加入一定量的铬合钼,具有防()腐蚀的作用。

A、一氧化碳

B、氢

C、二氧化碳

D、氮

题型:多项选择题

自我激励主要是要调整()。

A.他人的动机

B.自己的工资待遇

C.自我的动机

D.人际关系

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