试题与答案

下列物质中硫元素的化合价跟硫酸中硫元素的化合价相同的是( ) A.H2S B.S

题型:选择题

题目:

下列物质中硫元素的化合价跟硫酸中硫元素的化合价相同的是(  )

A.H2S

B.SO2

C.SO3

D.K2SO3

答案:

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to normal after eight hours. In a day, the chances of a heart attack decrease. In a year, the risk of heart

disease is half that of a smoker.

1. Most people who will die from smoking are from ____.

A. big countries  

B. small countries  

C. developing countries

D. developed countries

2. The author may hold the attitude(态度)that ______.

A. people can easily give up smoking  

B. people will feel much better after giving up smoking

C. it is not necessary for people to give up smoking forever

D. it is hard to say whether it is good to give up smoking or not

3. According to the American Cancer Society, after smokers stop smoking, the quickest effect is

   that ________.

A. the chances of having a heart attack get smaller

B. blood pressure returns to normal

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D. the risk of heart disease for a non-smoker is half that of a smoker

4. We can infer from the passage that________.

A. WTO officials say that a person will live longer if he / she stops smoking

B. the smoker can affect the health of his or her family members

C. following any way can help you stop smoking

D. no matter how hard you try it, it is worth doing that

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