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As a boy I was very weak. I didn't imagine me ________ a weight lifter.
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The government-run command post in Tunis is staffed around the clock by military personnel, meteorologists and civilians. On the wall are maps, crisscrossed with brightly colors arrows that painstakingly track the fearsome path of the enemy.
What kind of invader gives rise to such high-level monitoring? Not man, not beast, but the lowly desert locust(蝗虫). In recent months, billions of the 3-inch-long winged warriors have descended on Algeria, Libya, Morocco and Tunisia, blackening the sky and eating up crops and vegetation. The insect invasion, the worst in 30 years, is already creating great destruction in the Middle East and is now treating southern Europe. The current crisis began in late 1985 near the Red Sea. Unusually rainy weather moistened the sands of the Sudan, making them ideal seedbed for the locust, which lays its eggs in the earth. The insect onslaught threatens to create yet another African famine. Each locust can eat its weight (not quite a tenth of an ounce) in vegetation every 24 hours. A good-size swarm of 50 billion insects eats up 100,000 tons of grass, trees and crops in a single night.
All ﹩150 million may be needed this year. The U.S. has provided two spraying planes and about 50,000 gal. of pesticide. The European Community has donated ﹩3.8 million in aid and the Soviet Union, Canada, Japan and China have provided chemical-spraying aircraft to help wipe out the pests. But relief efforts are hampered by the relative mildness of approved pesticides, which quickly lose their deadly punch and require frequent replications. The most effective locust killer dieldrin has been linked to cancer and is banned by many Western countries and some of the affected African nations. More than 5 million acres have been dusted with locust-killing chemicals; another 5 million will be treated by the end of June.
On May 30, representatives of Tunisia, Algeria, Libya, Morocco and Mauritania will meet in Algiers to discuss tactics to wipe out the ravenous swarms. The move is an important step, but whatever plan is devised, the locust plague promised to get worse before the insects can be brought under control.
1.The main idea of the first sentence in the passage is that ______.
A. the command post is stationed with people all the time.
B. the command post is crowded with people all the time.
C. there are clocks around the command post.
D. the clock in the command post is taken care of by the staff.
2.The favorable breeding ground for the locust is ______.
A. rich soil. B. wet land
C. paces covered crops and vegetation D. the Red Sea
3.People are alert at the threat of the locust because ______.
A. the insects are likely to create another African famine.
B. the insects may blacken the sky.
C. the number of the insects increases drastically.
D. the insects are gathering and moving in great speed.
4.Which of the following is true?
A. Once the pesticides are used, locust will die immediately.
B. Relief efforts are proved most fruitful due to the effectiveness of certain pesticides.
C. Dieldrin, the most effective locust killer, has been widely accepted in many countries.
D. Over 10 million acres of affected area will have been treated with locust-killing chemicals by the end of June.
5. The purpose for affected nations to meet in Algiers on May 30 is ______.
A. to devise anti-locust plans.
B. to wipe out the swarms in two years.
C. to call out for additional financial aid from other nations.
D. to bring the insects under control before the plague gets worse.
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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