问题 选择题

下述实验能达到预期目的的是

编号实验内容实验目的
A将甲烷和乙烯的混合气体通过盛有溴水的洗气瓶除去甲烷中混有的乙烯
B在苯和苯酚的混合液中加入足量的浓溴水,振荡、过滤分离出苯酚
C淀粉溶液和稀H2SO4混合加热,后加新制的Cu(OH)2悬浊液加热至沸腾检验淀粉水解产物有还原性
D将乙醇与浓硫酸共热制得的气体通入酸性KMnO4溶液中检验气体中含有乙烯
 

答案

答案:A

A:正确

B:苯酚与溴水生成的三溴苯酚可溶于苯中,不正确

C:淀粉在酸性情况下水解后,必须加碱中和酸后,才能用新制的Cu(OH)2悬浊液加热至沸腾来检验水解产物的存在,不正确

D:硫酸的还原产物SO2同样能使酸性KMnO4溶液褪色,不正确

阅读理解与欣赏
阅读理解

Have you ever suddenly felt that someone you know was in trouble ― and he was? Have you ever dreamed something that came true later? Maybe you have ESP.

ESP stands for Extra Sensory Perception. It may be called a sixth sense. It seems to let people know about events before they happen, or events that are happening some distance away.

Here is an example: A woman was doing washing. Suddenly she shouted, “My father is dead! I saw him sitting in the chair!” Just then, a telephone came. The woman’s father had died of a heart illness. He died sitting in a chair.

There are thousands of stories like this on record. Scientists are studying them to find out what is behind these strange mental messages. Here’s another example —— one of hundreds of dreams that have come true.

A man dreamed he was walking along a road when a horse and carriage came by. The driver said, “There’s room for one more.” The man felt the driver was Death, so he ran away. The next day the man was getting on a crowded bus. The bus driver said, “There’s room for one more”. Then the man saw the driver’s face was the same face he had seen in the dream. He wouldn’t get on the bus. As the bus drove off, it crashed and burst into fires. Everyone was killed!

Some people say stories like these are lies or coincidences. Others say that are ESP in true, from studies of ESP, we may some day learn more about the human mind.

小题1:ESP lets people know about _________.

A.their dream

B.events after they happen

C.events before they happen

D.heart illness小题2:The example of the man shows the ability to _______.

A.avoid traffic accidents

B.know the good and bad of a person

C.know about the events happening some distance away

D.sense a danger that will happen later on小题3:The best title of this passage is _________.

A.Sixth Sense

B.The Human Mind

C.A Big Lie

D.A Terrible Dream