问题 选择题

由乙烯推测丙烯(CH2═CH-CH3)的结构或性质不正确的是(  )

A.能使酸性高锰酸钾溶液褪色

B.能在空气中燃烧

C.能使溴水褪色

D.与HCl在一定条件下能加成只得到一种产物

答案

A.含碳碳双键,能使酸性高锰酸钾溶液褪色,故A正确;

B.含C、H元素,燃烧生成二氧化碳和水,故B正确;

C.含碳碳双键,与溴水发生加成反应,能使溴水褪色,故C正确;

D.CH2═CH-CH3结构不对称,与HCl发生加成反应得到CH3CHClCH3、CH2ClCH2CH3,故D错误;

故选D.

阅读理解

Doctors say obesity,also known as severe overweight,is a complex condition.A doctor may advise medical interventions(医疗干预) in addition to changes in behavior.But experts say the more successful weight­loss plans include a well­balanced diet and exercise.

People who want to avoid weight gain have to balance the number of calories they eat with the number of calories they use.To lose weight,you can reduce the number of calories you take in,or increase the number you use,or both.Experts at the National Institutes of Health say to lose weight,a person should do some moderate or intensive physical exercise most days of the week.This could include fast walking,sports or strength training.

A recent study looked at four of the most popular dieting plans in the United States.Researchers at Stanford University studied more than three hundred overweight women,mostly in their thirties or forties.Each woman went on one of the four plans:Atkins,The Zone,Ornish or LEARN.The women attended diet classes and received written information about the food plans.At the end of a year,the women on the Atkins diet had lost the most,more than four and a half kilograms on average.

Christopher Gardner led the study,reported in the Journal of the American Medical Association. He said the Atkins diet may be more successful because of its simple message to lower the intake of sugar.Also,he said the advice to increase protein in the diet leads to more satisfying meals.

But last week,another report suggested that only a small minority of people have long­term success in dieting.Researchers at the University of California found that most dieters regained their lost weight within five years.And often they gained back even more.But those who kept the weight off generally were the ones who exercised.

小题1:All the following is helpful to lose weight EXCEPT________.

A.a healthy diet

B.physical exercise

C.medical interventions

D.being polite to others小题2:You are most likely to gain too much weight if________.

A.you eat the same number of calories as the number you use

B.you take in less calories than the number you use

C.you take in more calories than the number you use

D.you take exercise regularly on the weekdays小题3:The third paragraph mainly tells us that________.

A.there are four popular dieting plans in the USA

B.the Atkins diet has the best effect on losing weight

C.lots of women attended diet classes every day

D.dieting plan is the most important小题4:Which one of the following is NOT right according to this passage?

A.The change of your life habits can help you lose weight.

B.You’d better exercise once a week to lose some weight.

C.The Atkins diet may be good because of lowering the intake of sugar.

D.Some people gain weight back for their unhealthy diet.小题5:Which one of the following is the best title for this passage?

A.Successful Weight­loss Plans

B.Four Popular Dieting Plans

C.What Is the Atkins Diet?

D.Few People Fail in Losing Weight

多项选择题