题目内容：

As most people know, in the past few years, sandstorms have swept across many cities and areas of North China, polluting the air and disturbing daily lives of human beings. People look dirty and suffer many kinds of illnesses, such as breath difficulty. The sandstorm is such a serious problem that it has not only undermined the industrial and agricultural development of our country but also caused a lot of trouble to the living conditions of the Chinese people. It is expected that effective(有效的) measures should be taken as soon as possible through our joint efforts to limit its occurrence.

So what should we do with the frightening sandstorms? Some experts put forward practical suggestions as follows: For one thing, more funs(基金)ought to be put into tree planting and forest protection so as to keep more water resources within the surface of the earth. For another, governments of all countries should make laws on environmental protection.For example, banning the use of throw-away chopsticks and punishing illegal tree cutting. Scientists should also study and find ways to cut down the degree of its destruction and to improve the whole environment.

How people look forward to sunny days with little breeze(微风)touching their faces now and forever! Nevertheless, I am fully confident that the golden days can come back so long as everyone tried his best to protect natural environment from today on.

1.The underlined word”undermined”(in Paragraph 1)means __________.

A．weakened         B．encouraged        C．kept             D．made

2.From the first paragraph, we can infer _________.

A．China has taken no measures to prevent sandstorms.

B．sandstorms can cause much damage to human beings and their daily lives.

C．the sandstorm is the most dangerous natural disaster to human beings.

D．more sandstorms will happen in the near future in North China.

3.How many ways do some experts put forward to fight against sandstorm?

A．5                B．4                C．3                D．2

4.What’s the author’s attitude towards the situation to sandstorms’ problems?

A．Unconfident       B．Optimistic         C．Regretful          D．Satisfied