In the past hundred years, there have been frequent natural disasters, just like the following pictures show. What do you think mainly causes the disasters and what should we do next?

　　In the past hundred years, there have been frequent natural disasters, such as floods, droughts, mud­rock flows, seismic sea waves, earthquakes, windstorms and the stretching of new deserts. The disasters have killed millions of people, destroyed countless homes, and wiped out numerous pieces of fertile land.

　　Now more and more people become aware that those disasters have much to do with what we have done to the earth. We have cut down too many trees in the forests, we have badly polluted the environment, we have shocked our own home­planet time and again with tremendously powerful explosions of nuclear bombs. As a result, climates have become abnormal, rainwater rushes down hillsides angrily, and the underground energy goes up to revenge itself on us.

　　The earth is our only home­planet. It is urgent for us to stop damaging it, and to do our best to protect it and make it a lovely place suitable to live in, for we have nowhere to go and survive except where we are now.

　　Ⅰ.Fast­reading

　　Choose the best answers according to the text.

　　1．What's the main idea of the passage?

　　A．More and more natural disasters and their influences.

　　B．Volcanoes, the worst threat to human beings.

　　C．How to predict the natural disasters correctly.

　　D．The measures people have taken to prevent natural disasters.

　　2．From the passage, we can know that ________.

　　A．natural disaster can be predicted with the science development

　　B．more and worse nature disasters will come in the future

　　C．many countries have taken effective measures facing the natural disasters

　　D．global warming is the main cause of natural disasters

　　3．Why are volcanoes and earthquakes are more dangerous than before?

A．Because the earth is becoming warmer and warmer.