问题 选择题

单质分子由(  )

A.同一种元素的原子构成

B.同一种元素组成

C.同一种分子构成

D.同一种元素的两个原子构成

答案

A、单质是由一种元素组成的纯净物,分子是由原子构成的,所以单质分子是由同一种元素的原子构成,故A正确;

B、单质分子叙述的是分子要用原子解释,不能直接用元素组成解释,故B错;

C、同一种分子构成纯净物,构成的是一种物质,单质分子说的是分子的构成,应该用原子回答,故C错;

D、单质分子的构成不一定是由两个原子构成,例如臭氧分子是由3个原子构成,故D错.

故选A.

阅读理解

When you buy a T-shirt, or a fur coat in a store , it often carries a label(标签) telling who made it or from what store it was bought. Indeed, some labels show the dress is famous and it is very expensive, so buyers who deal with the cheapest products would be pleased to do away with labels entirely.

However, there is another label more important than the one showing from which store the dress was bought. When a person buys a fur coat, or a jacket , from a store , a label telling what the product is made of should be carried to it.

This label is required by law. Besides telling what the product on show is made of , the label should be in clear English and be where one can find it easily. The information on the label must be the truth.

The reason for this label is that most buyers today aren’t expert enough to know exactly what kind of fur or material they are buying. The buyer must believe in the store that sells the products or in what the labels say.

小题1:The author doesn’t agree that_______.

A.some clothes may carry more than one label

B.some clothing stores sell cheap dresses

C.shops can sell products with or without labels

D.buyers will believe what the label says小题2:This article mainly refers to__________.

A.making furs and clothes

B.protecting buyers with law

C.keeping the buyers informed

D.businessmen and sellers小题3:Which of the following is true?

A.Not all buyers know the materials they are buying.

B.A fur coat with a high price often carries a false label.

C.A label only says what material the product is made of .

D.A T-shirt seldom carries a label.

问答题 简答题