问题 选择题

下列各组中的物质,在水溶液中相互都不能发生反应的一组是(  )

A.Na2SO4 NaCl  Ba(NO32

B.HCl  Na2SO4 Na2CO3

C.CuSO4 KCl   KOH

D.KNO3  NaCl  MgSO4

答案

A、在水溶液中,硫酸钠和硝酸钡反应生成硫酸钡白色沉淀,故A不可选;

B、在水溶液中,盐酸和碳酸钠反应生成二氧化碳和水,故B不可选;

C、在水溶液中,硫酸铜和氢氧化钾生成氢氧化铜蓝色沉淀,故C不可选;

D、在水溶液中,硝酸钾、氯化钠、硫酸镁三种物质相互都不能发生反应,故D可选.

故选D.

阅读理解

Want to stay away from colds? Put on a happy face.

Compared to unhappy people, those who are cheerful and relaxed are less likely to suffer from colds, according to a new study. It’s possible that being happy helps the body fight illnesses, say the researchers from New York University.

“It seems that positive(积极的) feelings may reduce (减少)the danger of illness,” said the study’s chief researcher Sheldon Cohen.

In an earlier study, Cohen found that people who were cheerful and lively caught coughs and colds less often. People who showed feelings were also less likely to tell their doctors that they felt ill.

In this study, Cohen’s interviewed 193 adults every day for two weeks. During the interviews, the people told researchers about were given colds by doctors and had to stay alone in a room for six days.

The results showed that everyone in the study was equally(相等地) likely to get ill. Buy for people who said they felt happy during the research period, their illness are less serious and lasted for a shorter time.

Cohen believes that when people experience positive feelings, their body may produce a chemical that helps fight illness and disease. So if you are worried abut your health, look on the bright side more often.

小题1: What did the study find?

A.People who felt happy never got ill.

B.People’s feelings didn’t influence their health.

C.People with good feelings became ill more easily.

D.People with positive feelings had less serious illnesses.小题2:According to Cohen, which of the following may help fight illness?

A.Eating.

B.Crying.

C.Laughing.

D.Sleeping.小题3:This passage is a/an          .

A.advertisement

B.newspaper report

C.story

D.scientist’s diary小题4:What is the best title for this passage?

A.Smiles can fight colds

B.Cause of colds found

C.The danger of colds

D.How people get sick

问答题 论述题