1. Why do airplanes take longer to fly west than east?
It can take five hours to go west-east from New York(NY)to London but seven hours to travel east-west from London to NY. The reason for the difference is an atmospheric phenomenon known as the jet(喷射)stream. The jet stream is a very high altitude wind which always blows from the west to the east across the Atlantic. The planes moving at a constant air speed thus go faster in the west-east direction when they are moving with the wind than in the opposite direction.
2. What would happen if the gravity on Earth was suddenly turned off?
Supposing we could magically turn off gravity. Would buildings and other structures(建筑物)float away? What happened would depend on how strongly the things were attached to the Earth. The Earth is moving at quite a speed, moving at over a thousand miles per hours. If you turn something around your head on a string(细绳), it goes around in a circle until you let go of the string. Then it flies off in a straight line. ' Switching off gravity would be like letting go of the string. Things not attached to the Earth would fly off in a straight line. People in buildings wrould suddenly
shoot
upwards at a great speed until they hit the ceiling. Most things outside would fly off into space.
单选题
What information can we get from the first passage?
【正确答案】
A
【答案解析】解析：推理判断题。由第一段最后两句可知喷射汽车穿过大西洋时总是从西吹向东，因此飞机顺风飞行比逆风飞行速度快，故推出喷射气流影响飞行速度，故选A；B和第一段最后一句矛盾，句中的slower应该写成faster；C和第一段第一句意思相反，句中的more应该是less；D中的from the east to the west应该是from the west to the east，故排除。
单选题
The underlined word "shoot"in the 2nd passage probably means "______".
【正确答案】
B
【答案解析】解析：词义猜测题。A项意为“派人去请”；B项意为“快速移动”；C项意为“出现，显露，结果是”；D项意为“快速生长”。由本句中的“upwards at a great speed”可知“shoot”的意思应该是“快速移动”。故选B项。
单选题
It can be inferred that without gravity______.