题目内容：

The year is 2094,It has been announced that a comet is heading towards the Earth.Most of it will miss our planet, but two pieces will probably hit the southern half of the Earth.

On 17 July, a piece four kilometers wide enters the Earth’s atmosphere with a massive explosion.About half of the piece is destoryed but the remaining part hits the South Atlantic at 200times the speed of sound.The sea boils and a huge gole is made in the sea bed.Huge waves are created and spread outwards form the hole.The eall of water,a kilometer high,rushes towards southern Africa at 800 kilometers an hour.Cities on the African coast are totally destroyed and millions of people are drowned.

Before the waves reach South America.the second piece of the comet lands in Argentina.Earthquakes and volcanoes are set off in the Andes Moutains.The shock waves move north into California and all around the Pacific Ocean. The cities of Los Angeles,San Francisco and Tokyo are completely destroyed by earthquakes,Millions of people in the southern half of the earth are already dead,but the north won’t eacape for long.Because of the explosions the sun is hidden by clouds of dust,and temperatures around the world fall to almost zero.Crops are ruined.The sun won’t be seen again for many years.Wars break out as countries fight for food.A year later,no more than 10 million remain laive.

Could it really happen?In fact,it has already happened more than once in the history of the Earth.The dinesaurs were on the Earth for over 160 million years,Then 65 million years ago they suddenly disappeared.Many scientists believe that the Earth was hit by a piece of object in space. The dinosaurs couldn’t live through the cold climate that followed and they died out .Will we meet the same end ?

1.What is mainly described in the passage ?

A.A historic discovery B.A research on space

C.A scientific adventure D.An imaginary event

2.When the first piece hits the South Atlantic,it causes_______.

A.an earthquake  B.huge waves

C.damages to cities  D.an Earth explosion

3.Why can’t the northern half of the earth escape ofr long?

A.Because the land is covered with water.

B.because people there can not live at the temperature of zero.

C.Because wars break out among countries.

D.Because the light and heat from the sun can not reach the earth.

4.By giving the example if dinosaurs,the author tries to prove________.

A.animals could not live in the cold climate.

B.what happened 65 mollion years ago was an invented story.

C.the human beings will die out in 2094

D.the Earth could be hit by other objects in space

5.We may guess that the writer is_________.

A.worried   B.full of imagination C.practical D.a scientist