Have you ever wondered?
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 (大气现象) known as the jet stream (气流). The jet stream is a very high altitude (=" above" sea level) wind which always blows from the west to the east across the Atlantic. So the planes moving at a constant air speed go faster from the west to the east when they are moving with the wind than in the opposite.
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 (依靠) how strongly the things were attached (吸附) to the earth. The earth is moving at quite a speed, moving at over a thousand miles per hour. If you turn something around your head on a string, it goes around in a circle until you let go of the string. Then it flies off in a straight line. ‘Turning 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 would suddenly shoot upwards at a great speed until they hit the ceiling (=" top" surface of a room). Most things outside would fly off into space.
【小题1】What information can we get from the first passage?

阅读短文，从方框中选出适当的词，并用其适当形式填空。有的需要加助动词或不定式符号。(每词限用一次)

Many people have heard of Barack Obama—the first African-American president. While Obama （1）_____________ in high school, he showed much talent in study. After graduating from university, he worked as a teacher. And he  (2) ______________ some books since 1995. These books help him earn millions of dollars. He gives away some of the money to charities. He (3) ____________ the President of the USA in the year 2008.
Most of the American people (4) _____________ confidence in Obama. They believe that a bright future (5) ____________ to them soon.

Just a Little Smile
Mark was walking home from school one day when he saw the boy in front of turn fall over and drop all of the books he was carrying, along with two sweaters, a basketball and a walkman (随身听). Mark stopped and helped the boy pick up these things. Since they were going the same way, he helped to carry some of his things. As they walked, Mark knew that the boy’s name was Bill, that he loved computer games, basketball and history, and that he was having lots of troubles with his other subjects and that he had just broken up with his girlfriend.
They arrived at Bill’s home first and Mark was invited(邀请) in for a Coke and to watch some television. The afternoon passed happily with a few laughs and some small talk, then Mark went home. They often saw . each other at school, had lunch together once or twice, and then they both finished middle school. They ended up in the same high school where they sometimes saw and talked with each other over the years. At last just three weeks before they finished high school, Bill asked Mark if they could talk.
Bill asked Mark if he still remembered the day years ago when they had first met. "Did you ever think why I was carrying so many things home that day?" asked Bill. "You see, I cleaned out my locker(锁柜) because I didn’t want to leave anything for anyone else. I had put away some of my mother’s sleeping pills and I was going home to kill myself. But after we spent some time together talking and laughing, ! began to understand that if I killed myself, I would have missed that time and so many others that might follow. So you see, Mark, when you picked up those books that day, you did a lot more. You saved my life. "
【小题1】 When Mark met him the first time, Bill was going

Sales of laptop computers passed desktops in the U.S. for the first time ever this fall, according to market-research firm IDC. That's bad news for backs, necks and shoulders.
Laptops are bad for our body. When you work at a computer, the keyboard should be at elbow height and the monitor should be roughly at eye level, so you can sit well in a chair. But most users simply set their laptops on a desk or table. The keyboard is too high, which makes your arms reach up, your shoulders feel tired and your wrists bend down. The monitor is too low, which pulls your head and neck forward and down and your back may feel hurt.
That's OK if you use your laptop for a short time. But if you use one for hours without stopping – as do millions of college students, business travelers, telecommuters, video-gamers and growing numbers of office workers – your body may feel hurt. Ergonomics experts have warned about laptop problems for years. But people still like laptops better than the desktops. And they use laptops anywhere – in bed, on the floor – in all kinds of positions.
“How can a mouse or a keyboard hurt you?” says Thomas Caffrey, the founder of Myofactors LLC, “Wrong positions can be bad for your body. As time goes by, a wrong position can lead to pain in the neck, shoulders, back and arms, as well as headaches.”
【小题1】When you work at a computer, the keyboard should be ________.