问题 单项选择题

下列各组物质,分别取等物质的量在足量的氧气中完全燃烧,耗氧量不同的组是( )。

A.乙烷(C2H5)和甲酸乙酯(C3H6O2)
B.乙炔(C2H2)和乙醛(C2H4O)
C.乙酸(C2H4O2)和乙醇(C2H6O)
D.乙烯(C2H4)和乙醇(C2H6O)

答案

参考答案:C

解析: 本题中各组物质是取等物质的量在足量氧气中完全燃烧。按照燃烧规律法采取转换形式:
选项A:C2H6和C3H6O2→转换成C2H6和C2H6·CO2,耗氧量相同;
选项B:C2H2和C2H4O→转换成C2H2和C2H2·H2O,耗氧量相同;
选项C:C2H4O2和C2H6O→不能转换成CxHy(CO2)m(H2O)n形式,耗氧量不同;
选项D:C2H4和C2H6O→转换成C2H4和C2H4·H2O,耗氧量相同。

阅读理解

We all know that theme parks are places to have fun and amuse ourselves, but among so many exciting rides there are also some dangers, Make sure you know what the safety standards are for all the attractions at the park. If you do that , you will be safe and have fun.

Drink water. Believe it or not , dehydration-- when your body doesn’t have enough water--is the commonest cause of injuries at theme parks. Drinking water while you are at the park is not enough.You must make sure that you drink enough water before your visit.

Use your “common sense”. There are lots of people around , so make sure where your friends or family are .Also ,if you are walking and want to stop , make sure nobody is walking behind you. First step aside,then look behind and if you aren’t in anybody’s way,then stop.It might sound exaggerated(夸张的),but crashes between people can cause accidents.

Follow the instructions. The majority of theme parks have instructions for each ride. Some rides only allow people of a certain height. So make sure you are not too tall or too short before boarding any ride. Also, people with certain diseases or conditions are advised not to go on some rides. Do remember : If you are told not to go on a ride, then DON’T.

Do not ride with a bad atomach or if you’ve just eaten. Rides can make you ill because of their violent changes of direction and your lunch may end up on someone else’s head: surely not a very pleasant experience.

Have fun, relax, and be a little brave!

Some rides might look scary but theme parks are very safe places.

小题1:What is the leading reason for injuries at theme parks?

A.Snow

B.Dehydration

C.Fire

D.Crashes小题2:According to the author,____.

A.it doesn’t pay to go to theme parks

B.people can have lots of fun in theme parks

C.men are more interested in theme parks than women

D.shy people should not go to theme parks小题3:Which of the following will the author accept?

A.Children should notplay in theme parks.

B.One shouldn’t eat anything before riding.

C.One must always stay with his friends or family in theme parks.

D.One must read the instructions before playing in theme parks.

单项选择题