写作（满25分）

　假如你是一个中学生名叫李晓华，根据以下信息给21 世纪报纸的编辑Ralph写封信。

注意：词数100左右。

Dear Ralph,

________________________________________________________________

Yours sincerely,

Li Xiaohua

Force other than damaging winds are also at work inside tornadoes. Sometimes, as the turning, jumping funnel(漏斗) passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion(爆炸) is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57,600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the great inside pressure may cause the building to burst.

　　Unfortunately, heavy rain happens in thunderstorms that later produce tornadoes. So, people often shut all windows to protect their property. This may cause far worse damage later.

63. Which of the following is the main topic of the passage?

A. Where tornadoes are formed.  　　      B. When tornadoes usually occur.

C. How tornadoes can be prevented.　　     D. Why tornadoes cause so much damage.

64. According to the passage, tornadoes can destroy building because the _____.

A. force of a tornado increases the air pressure in a building

B. air pressure at the center of a tornado is over 172,000 pounds

C. weight of a tornado can crush a building’s roof when it passes overhead

D. air pressure inside a tornado is less than the air pressure inside a building

65. According to the passage, the pressure on a building during a tornado can be reduced　　　　by _____.

A. closing the windows 　　　　　        B. opening the windows

C. using an electric fan 　　　　          D. making the roof and walls stronger

写作（满25分）
　假如你是一个中学生名叫李晓华，根据以下信息给21 世纪报纸的编辑Ralph写封信。
注意：词数100左右。

In July 1994 Jupiter, the largest planet in our solar system, was struck by 21 pieces of a comet (彗星). When the fragments (碎片) landed in the southern part of the giant planet, the explosions(爆炸) were watched by scientists here on the earth. But what if our own planet was hit by a comet?

　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 fragments will probably hit the southern part of the Earth. The news has caused panic.

　On 17 July, a fragment, four kilometers wide, enters the Earth's atmosphere with a huge explosion. About half of the fragment is destroyed. But the major part survives and hits the South Atlantic at 200 times the speed of sound. The sea boils and an enormous(巨大的) wave is created and spreads. The wall of water rushes towards southern Africa at 800 kilometres an hour. Cities on the African coast are totally destroyed and millions of people are drowned. The wave moves into the Indian Ocean and heads towards Asia.

　Millions of people are already dead in the southern part of the Earth, but the north won't escape for long. Tons of broken pieces are thrown into the atmosphere by the explosions. As the sun is hidden by clouds of dust, temperatures around the world fall to almost zero. Crops are ruined. Wars break out as countries fight for food. A year later civilization has collapsed(崩溃). No more than 10 million people have survived.

　Could it really happen? In fact, it has already happened more than once in the history of the Earth. The dinosaurs 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 space fragment. The dinosaurs couldn't survive in the cold climate that followed and they became extinct. Will we meet the same end?

1.Which of the following is NOT TRUE according to the author's description of the disaster in 2094?

A. The whole world becomes extremely cold

B. All the coastal cities in Africa are destroyed

C. The visit of the comet results in wars

D. The whole mankind becomes extinct

2.Why does the author mention dinosaurs at the end of the passage?

A. Because they could only live in the warm climate

B. Because their extinction indicates future disasters

C. Because they once dominated(控制) the earth

D. Because dinosaurs and humans never live in the same age

3. In writing the passage, the author intends to ______.

A. give an accurate description of the possible disaster in the future

B. prove that humans will sooner or later be destroyed

C. warn of a possible disaster in the future

D. tell the historical development of the Earth

4.It can be concluded that the passage is most probably part of a(n) ______.

A. article of popular science      B. news report

C. research paper                      D. horror story

Force other than damaging winds are also at work inside tornadoes. Sometimes, as the turning, jumping funnel(漏斗) passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion(爆炸) is caused by the low air pressure at the center of a tornado.
The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57,600 pounds. The pressure on the four walls adds up to 172,800 pounds.
If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the great inside pressure may cause the building to burst.
　　Unfortunately, heavy rain happens in thunderstorms that later produce tornadoes. So, people often shut all windows to protect their property. This may cause far worse damage later.
63. Which of the following is the main topic of the passage?
A. Where tornadoes are formed. 　　      B. When tornadoes usually occur.
C. How tornadoes can be prevented.　　     D. Why tornadoes cause so much damage.
64. According to the passage, tornadoes can destroy building because the _____.
A. force of a tornado increases the air pressure in a building
B. air pressure at the center of a tornado is over 172,000 pounds
C. weight of a tornado can crush a building’s roof when it passes overhead
D. air pressure inside a tornado is less than the air pressure inside a building
65. According to the passage, the pressure on a building during a tornado can be reduced　　　　by _____.
A. closing the windows 　　　　　        B. opening the windows
C. using an electric fan 　　　　          D. making the roof and walls stronger