问题 选择题

下列关于化学键的说法正确的是(  )

①含有金属元素的化合物一定是离子化合物

②第IA族和第ⅦA族原子化合时,一定生成离子键

③由非金属元素形成的化合物一定不是离子化合物

④活泼金属与非金属化合时,能形成离子键

⑤离子键就是阴、阳离子间的相互引力

⑥含有离子键的化合物一定是离子化合物

⑦离子化合物中可能同时含有离子键和共价键

A.①②⑤

B.④⑥⑦

C.①④③

D.②③⑤

答案

答案:B

AlCl3是共价化合物,故①错误;第ⅠA族的H和第ⅦA族原子化合时,形成的是共价键,②错误;氯化铵全部是由非金属元素组成,但是它是离子化合物,③错误;离子键就是阴、阳离子间的相互作用,包括引力和斥力,⑤错误。

选择题
阅读理解

阅读下面短文,请根据短文后的要求进行答题。(请注意问题后的字数要求)

     [l]Compared to people with bad attitudes, people _____ are less likely to suffer from colds. It's possible

that being positive helps the body fight illnesses.

     [2]In a previous study, people who tended to be cheerful and lively were least likely to develop coughs

and other cold symptoms. People who showed positive feelings were also less likely to mention symptoms

to their doctors, even when medical tests detected those symptoms.

     [3]Those findings were interesting, but they didn't prove that a person's attitude affects whether he or

she gets sick. Instead, it was still possible that a person's underlying personality is what matters.

     [4]Evidence suggests, for instance, that certain people are naturally more likely to be outgoing and

optimistic, with high self-esteem and a sense of control over life. This would mean that who we are, not

how we feel, ultimately decides our chances of catching colds.

     [5]To figure out which mattered more, personality or emotions, the researchers interviewed 193 healthy

adults. The results showed that everyone in the study was equally likely to get infected. Their symptoms,

however, differed depending on the types of emotions that they had reported over the previous fortnight.

     [6]Among those who reported good moods and had been infected with the flu virus, for example, 28

percent developed coughs and stuffy noses. On the other hand, those symptoms struck 41 percent of people

who had been less positive.

     [7]Scientists argue about whether negative emotions or positive emotions have a stronger effect on how

healthy we are. For now, it can't hurt to look on the bright side more often than not!

1. What's the main idea of the passage? (Please answer within 10 words)

    _____________________________________________________________________________________

2. Fillin the blank with proper words in the first paragraph (Please answer within 10 words) 

    _____________________________________________________________________________________

3. Which sentence in the passage can be replaced by the following one? But, their symPtoms were closely 

    related to the emotions they had claimed to have in the last two weeks.

    _____________________________________________________________________________________

4. Translate the underlined sentence in the third paragraph into proper Chinese.

    _____________________________________________________________________________________

5. Suppose one of your friends had got infected with the HINI flu give him/her at least three pieces of advice.

    (Please answer within 30 words)

    _____________________________________________________________________________________