题干

某烃有两种或两种以上的同分异构体,其同分异构体中的某一种烃的一氯代物只有一种,则这种烃可能是(    )
①分子中具有7个碳原子的芳香烃  ②分子中具有4个碳原子的烷烃
③分子中具有5个碳原子的烷烃    ④分子中具有8个碳原子的烷烃

A:①②  

B:②③  

C:③④ 

D:②④

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答案(点此获取答案解析)

C

同类题4

任务型阅读

    In the United States, teenagers can only get a full-time job if they are 16 years old or older. But there are things that the younger teenagers can do to make some money. Here are a few examples.

    Parents with young children sometimes want to go out for dinner or to the movies, but they don't want to leave their children at home alone (单独).____If the children go to bed early, the teenager can do some of his or her homework!

Some people have a dog, but they don't have time to take it for a walk. Dogs need a lot of exercise!____It's a good idea – they can make money and stay outside in the fresh air. They get some exercise, too!

    Teenagers can deliver (递送) newspapers. ____ They need to have their own bike. They have to get up early, too, because people want to read their newspaper at breakfast.

    Teenagers can also work at home on their computer. Some companies (公司) pay teen, agers to make online surveys (调查).____ It's a fun and easy way to make money.

    These are all popular jobs. Teenagers can choose one of them to make some money. ____ Beijing safe is the most important thing after all. "

根据材料内容,从方框中选择合适的句子填入文中空缺处,使短文完整、通顺。

A. So some teenagers work as dog walkers.

B. So they ask a teenager to stay in the house and look after (照顾) their children when they are out.

C. Before they do their jobs, they usually tell someone about what they're doing.

D. They want to know what teenagers are interested in.

E. They usually ride a bike around a neighborhood and leave newspapers at each house.