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问题 单项选择题 A1/A2型题

二萜相当于（）

A.两个异戊二烯聚合

B.三个异戊二烯聚合

C.四个异戊二烯聚合

D.五个异戊二烯聚合

E.六个异戊二烯聚合

答案

参考答案：C

解析：二萜类物质是由4个异戊二烯单元聚合而成的化合物及其衍生物。

阅读理解
阅读理解。
Dear Dr. Know,
     Can you help me? My life is awful! I have many rules! I have to get up at six o'clock every
morning. My mom has to work at five a.m., so I have to cook breakfast! After breakfast, I run
to school because I can't be late. At school, I have even more rules-don't be noisy, don't eat in
class.
     After school, Dad says I can't hang out with my friends. I can only hang out with them on
weekends. I can't even relax after dinner. Why? Because that's another rule-Do my homework
after dinner. Then I watch TV. I even have rules for sleeping! I have to go to bed before ten
o'clock. Rules, rules, rules! They're making me crazy! What can I do, Dr. Know?
                                                                                                                            Yours,
                                                                                                                             Tim

Dear Tim,
     Sometimes we have a hot of rules in our life. But remember, parents and schools make rules
to help us. We have to follow them. Good luck!
                                                                                                                        Dr. Know
1. Tim is unhappy because _____.
A. he has to work at 5 a.m.
B. he has many rules
C. he can't study at home
D. he can't sleep well
2. Tim can hang out with friends _____.
A. after school
B. in the evenings
C. on weekends
D. in summer vacations
3. Dr. Know tells Tim that _____.
A. he needn't obey the rules
B. he has less rules at home
C. school rules are more important
D. parents make rules to help him
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单项选择题

一初孕妇，早期妊娠患有感冒，口服感冒灵3天，出现情绪紧张，与哪种因素有关（）。

A、缺乏妊娠知识

B、害怕中毒

C、害怕分娩困难

D、担心胎儿畸形
查看答案