的小球P从物体A正上方距其高度h处由静止自由下落，与物体A发生碰撞（碰撞时间极短），碰后A和P粘在一起共同运动，不计空气阻力，重力加速度为g。
的小球Q从物体A正上方某一高度由静止自由下落，与物体A发生弹性碰撞（碰撞时间极短），碰撞后物体A达到最高点时，地面对物体B的弹力恰好为零。求Q开始下落时距离A的高度。（上述过程中Q和A只碰撞一次）
On the day the tornado hit, there was no indication severe weather was on its way—the sky was blue and the sun had been out. The first warning my husband, Jimmy and I got came around 9 p.m., from some scrolling text on the TV Jimmy was watching.
No sooner had we found coverage of the tornado than it was on top of us. I didn’t know how or if we would make it down the steps. It felt as if there were no floor underneath me as the wind lifted me off my feet. I gripped the banister(楼梯扶手) and tried to move forward, but this intense pressure held me in place. In those seconds of practical stillness, I could hear everything around me rattling.
We got close to the staircase landing only to hear the loud ripping（撕裂） sound of our garage door coming off. The back wall of the house followed suit and tore off into the darkness outside.
By the time I reached the closet, the tornado had been over us for about a minute. Jimmy pushed me down to the closet floor, but he couldn’t get inside himself because of the wind. I held Jimmy’s arm tightly as the tornado sucked the door open—we never did get it fully shut—and tried to bring Jimmy with it. My knees and head were full of glass, but in that moment, I felt no pain. If I had let go, Jimmy would have flown right out the back of the house and into the bay.
“Hold on! Hold on!” he yelled. But there was nothing in this closet to hold on to. All of a sudden, Jimmy lifted off his feet like people in tornadoes do in the movies. I thought he was gone. And then everything stopped. He landed on his feet. In those first quiet moments, I couldn’t believe it was over. Jimmy said he’d go outside to check. “No,” I said. “Don’t leave me. Don’t leave me.”
1．What does the underlined word coverage mean?| A．damage | B．reports |
| C．arrival | D．delay |
| A．Because she was too eager to help her husband to feel it. |
| B．Because she was frozen in amazement. |
| C．Because she was held entirely by the power of tornado. |
| D．Because she was frightened by the damage caused by the disaster. |
| A．scared, surprised but calm | B．surprised, terrified but determined |
| C．astonished, confused and moved | D．amazed, determined and grateful |
My great-grandmother Eileen is fierce, loyal and strong and a bit of a legend in her lifetime, which now stretches to 92 years. We’re not allowed to call her Gran, because it makes her feel old.
That summer, I lost my job and felt hopeless. One day, I visited her. She picked up a box. “There you go,” she said. “You are good at these things, aren’t you?” It was a new phone. Her current mobile was ancient. I was surprised it still worked.
“Yes, ”I said. “That’s why I ask you. Young people know more about such things than us oldies. You can take it home and get it all set up,” she went on. “Then, when you bring it back, you can show me how to use it, such as surfing the Internet, sending e-mails and so on.” She smiled so sweetly that I felt a surge of love for her.
I grabbed the box. Setting up the phone would be easy. It was teaching her how to use it that may prove challenging. The following day I headed back to my great-grandmother’s with the phone.
“Here’s your phone. All ready to use.” For the next hour, I was busy setting up her passcode and fingerprint recognition, which she said was like something out of James Bond.
She chose a picture for her screen and it was all going so well until I tried to show her how to swipe（滑动屏幕）. “Swipe?” she asked. She was 92, I reminded myself. This had been tiring for her.
She pressed at the up arrow and got angry when nothing happened. When I finally got her to swipe, she didn’t put the right amount of pressure on and the menu slipped away. After what seemed like hours, she threw the phone on the sofa. “Take it away!” she howled. “I want my old phone back!”
I picked up the phone and was about to leave to give her time to cool down when I realized I didn’t want to go home when she was angry and upset.
“Come on, Eileen. One more try.” I said.
Seeing this, I was not feeling hopeless any more.
，函数
的最小值记为
，给出下面四个结论：的最小值为0；的最大值为3；在
上单调递减，则
的取值范围为
；
，对于任意的
，
，则的可能值共有4 个；
在
上非严格递增，满足
，若存在符合上述要求的函数及实数
，满足
，则的取值范围是为定义域
上单调函数，且存在区间
（其中
），使得当
时，的取值范围恰为
，则称函数是D上的正函数，区间叫做等域区间.
是
上的正函数？若存在，请求出实数m的取值范围；若不存在，请说明理由.
，且不等式
的解集恰为
，求函数
的解析式.并判断是否为函数的等域区间. 
的长度均为
，多个区间并集的长度为各区间长度之和，例如，
的长度
．用
表示不超过x的最大整数，记
，其中
．设
，当
时，不等式
解集的区间长度为
，则实数k的最小值为（ ）．A． | B． | C．6 | D．7 |
，求证：对于整数
，有
． 
．
时，求函数的最值；
，其中
为函数的导函数，试讨论函数
在
的零点个数． 
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