以下是某课题组设计的合成聚酯类高分子材料的路线: 已知:①A的相对分子质量小于

题型:推断题

问题:

以下是某课题组设计的合成聚酯类高分子材料的路线:

已知:①A的相对分子质量小于110,其中碳的质量分数约为0.9;②同一碳原子上连两个羟基时结构不稳定,易脱水生成醛或酮:

③C可发生银镜反应。请根据以上信息回答下列问题:

(1)A的分子式为_____________;

(2)由A生成B的化学方程式为_________________________________,反应类型是___________;

(3)由B生成C的化学方程式为_________________________________,该反应过程中生成的不稳定中间体的结构简式应是________________;

(4)D的结构简式为_________________,D的同分异构体中含有苯环且水解产物之一为乙酸的有_______________________________________(写结构简式)。

考点:有机物的推断
题型:推断题

可诱导机体产生免疫耐受的抗原称为()。

A.半抗原

B.变应原

C.耐受原

D.超抗原

E.丝裂原

题型:推断题

Become a confident speaker. How to improve your English speaking skills and make you able to communicate more easily and effectively? The following tips will help you to become a more confident speaker.

Practice where you can and when you can. And practice is good — whether you speak to someone who is a native English speaker or not.

It’s important to build up your confidence. If possible, use the simple sentence structure that you know is correct, so that you can concentrate on getting your message across.

Try to experiment with the English you know. Apply (应用) words and phrases you know to new situations. Native English speakers are likely to correct you if you use the wrong word. They usually don’t mind if you use wrong grammar.

Try to respond to what people say to you. You can often get clues to what people think by looking at their body language. Respond to them in a natural way.

Never translate everything into your own language. It takes you much time and you’ll find it difficult to find an English answer right away. You don’t know how to do well. The more you want to act well, the more slowly you act. This will make you hesitant.

If you forget a word, do what native English speakers do all the time, and say things that ‘fill’ the conversation. This is better than remaining completely silent. Try using ‘um’, ‘er’, if you forget the word.

Don’t speak too fast! It’s important to use a natural rhythm (节奏) in speaking English, but if you speak too fast it will be difficult for people to understand you.

Try to relax when you speak, and you’ll find that your mouth does most of the pronunciation work for you. Speak English at a normal speed.

Final tips: Try to become less hesitant. Don’t be shy to speak — the more you do it, the more confident you’ll become. Remember to be polite — use “please” and “thank you” if you ask someone to do something for you.

小题1:What is the text mainly about?

A.Good ways of studying English well.

B.Suggestions on becoming a confident speaker.

C.Things to pay attention to when speaking English.

D.How to correct your mistakes as you speak English.小题2:How many tips does the author offer in this text?

A.9.

B.10.

C.11.

D.12.小题3:In this passage, the underlined word “hesitant” in the sixth paragraph means “________”.

A.sure about what to do

B.fast to make a good decision

C.successful in answering questions

D.uncertain about how to express yourself小题4:This text is most probably written for ________.

A.English beginners

B.native English speakers

C.English teachers

D.language experts

题型:推断题

分馏塔顶冷回流线吹扫时,应()。

A、由汽油泵给汽,向冷回流控制阀处吹扫

B、由冷回流控制阀处给汽,向分馏塔处吹扫

C、由汽油泵处给汽,向分馏塔内吹扫

D、由冷回流控制阀处给汽,向汽油泵处吹扫

题型:推断题

下面哪一个B737-600传感器可导致管道过热信号()。

A.管道过热传感器190°F

B.压气机出口过热电门390°F

C.涡轮进口过热电门210°F

D.冲压空气温度传感器230°F

题型:推断题

甲企业以融资租赁方式租入A设备,该设备的公允价值为100万元,最低租赁付款额的现值为93万元,甲企业在租赁谈判和签订租赁合同过程中发生手续费、律师费等合计为2万元。甲企业该项融资租入固-定资产的入账价值为( )万元。

A.93
B.95
C.100
D.102

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