问题 选择题

下列说法正确的是

A.食盐由离子构成,它的水溶液不能导电

B.可用水除去生石灰中少量的碳酸钙

C.可以用水区分氯化钠和硝酸铵两种白色固体

D.可用明矾区分硬水和软水

答案

答案:C

本题考查的是溶液的导电性,物质的鉴别和除杂。

A、食盐由离子构成,它的水溶液中含有自由移动的阴阳离子,故能导电,说法错误;  

B、生石灰中含有少量的碳酸钙不能水除去,因为生石灰能与水反应,故说法错误;

C、硝酸铵固体溶于水时会吸热降温,而氯化钠溶于水时温度变化不大,故可以用水区分,说法正确;

D、区分硬水和软水要用肥皂水,泡沫多的为软水,浮渣多的为硬水,明矾为絮凝剂,不能区分,说法错误。故选C

判断题
阅读理解

A bowl of soup a day could keep the pounds at bay.

Health experts have discovered that adding low-calorie vegetable soup to the start of a meal can actually help to lose weight. Because you tend to feel full sooner, you eat less of your main course.

The soup method was tested by researchers at Pennsylvania State University, led by Dr Barbara Rolls. They found that when participants in the study ate a first course of soup before lunch they reduced their total calorie intake by 20 per cent, compared with those who did not begin the meal with soup. But those who favour creamy soups should beware. Researchers stressed the soup must be low-calorie and based on stock, not cream.

All of the soups tested in the study were made from the same elements—chicken stock (原汁鸡汤), broccoli (菜花), potato, cauliflower (花椰菜) and carrots. They were mixed together to create four different textures and thickness from separate stock and vegetables through to pureed (蔬菜泥) soup.

Scientists thought that thick soups with thick pieces of vegetables which required chewing might be more filling, but to their surprise they found all forms had the same effect. The findings were presented to the Experimental Biology conference in Washington, DC, and the research was part funded by the National Institutes of Health. 

小题1:The passage mainly discusses _____.

A.how to lose weight in a simple way

B.what kind of soup to be served at a meal

C.how to form a healthy eating habit

D.why eating soup could help lose weight小题2: What does the sentence “A bowl of soup a day could keep the pounds at bay” imply?

A.Eating soup equals to swimming in a sea.

B.Eating a bowl of soup every meal is enough to keep fit.

C.Eating soup every day can help you to lose weight.

D.Making soup every day could cost you a lot of money.小题3: Which of following is the possible result of eating soup before a meal?

A.Dropping the amount of calorie intake.

B.Reducing your weight by 20%.

C.Doing good to your growing high.

D.Helping you eat more.小题4: Which of the following statements is correct in making the soup?

A.The materials for making soup must be limited to vegetables.

B.The soup must be made low- calorie.

C.The thickness of the soup makes a difference.

D.The soup must be mixed with some cream.