用S表示梯形的面积，用a，b分别表示上底和下底，h表示高，则h=（ ）。
题型：填空题
问题：
用S表示梯形的面积，用a，b分别表示上底和下底，h表示高，则h=（ ）。
题型：填空题
| 完形填空。 | |||
| Tom had a beer in a bar and he was asked to pay $6.50 by the boss. "But I paid you just now. Don't you __1__ ?" Tom replied. "OK," said the boss, "If you said you paid, you did. " Then Tom __2__ the bar excitedly. When he met his friend, Jim, he told Jim his __3__ about what had just happened to him. "The boss of the bar doesn't have a good memory. He __4__ remember whether his customers have paid or not. Why not go to the bar and have a __5__ beer?" Tom suggested. To Jim, it sounded like a __6__ idea. He rushed into the bar,ordered two beers and later played the same trick (伎俩) on the boss. Jim paid __7__ for his beer. Soon, John heard Tom and Jim's stories. He didn't want to miss the chance to try his __8__. So John hurried into the bar. When he was drinking, the boss said, were drinking beer. Neither paid, __8__ both said that they had. The next guy who tries that trick will be __9__out of the window. " "Don't tell me about your problem," John said. "Just give me my change and I'll be on my way home. | |||
| ( ) 1. A. understand ( ) 2. A. left ( ) 3. A. book ( ) 4. A. mustn't ( ) 5. A. free ( ) 6. A. strange ( ) 7. A. everything ( ) 8. A. truth ( ) 9. A. if ( ) 10. A. paid | B. remember B. set B. boss B. must B. cheap B. boring B. nothing B. result B. so B. broken | C. expect C. repaired C. wine C. can't C. fresh C. good C. anything C. luck C. or C. thrown | D. suppose D. began D. story D. can D. favourite D. stupid D. something D. experiment D. but D. looked |