题干

2015年国际乒联世界巡回赛瑞典公开赛落下战幕,中国乒乓球队包揽男女单打、男女双打四个冠军.在比赛中,乒乓球先后两次落台后恰好在等高处水平越过球网,过网时的速度方向均垂直于球网,把两次的乒乓球看成完全相同的两个球,球1和球2,如图所示,不计乒乓球的旋转和空气阻力,乒乓球自起跳到最高点的过程中,下列说法中正确的是(  )

A:起跳时,球1的重力功率等于球2的重力功率

B:球1的速度变化率小于球2的速度变化率

C:球1的飞行时间大于球2的飞行时间

D:过网时球1的速度大于球2的速度

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答案(点此获取答案解析)

A,D

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阅读下列短文,从每题所给的 A、B、C 和 D 四个选项中,选出最佳选项。

    A Canadian man is asking forgiveness for a birdbrained thing he did 17 years ago: inadvertently(无心地) encouraging seagulls to trash his hotel room.

    Back in 2001, Burchill checked into the Fairmont Empress Hotel in Victoria, B.C, for a business meeting. He brought a small suitcase full of Brothers Pepperoni from his hometown to share with former Navy buddies in the area. But his room had no fridge so he opened a window to keep it cool. And then he went for a long walk. That was when things got messy. Really messy. The result was such a housekeeping nightmare that the hotel permanently banned him.

    “I remember walking down the long hall and opening the door to my room to find an entire flock of seagulls in my room. There must have been 40 of them and they had been eating pepperoni for a long time.” Burchill said.

    When he walked into the room, Burchill recalled he frightened the birds. They “immediately started flying around and crashing into things as they desperately tried to leave the room.” The result was a tornado of seagull feathers, pepperoni chunks and fairly large birds whipping around the room. The lamps were     falling. The curtains were trashed. The coffee tray was just disgusting.

    Eventually, Burchill called the front desk and requested help cleaning up the room. “I can still remember the look on the lady's face when she opened the door. ”said Burchill. A short time later, he received a note from the hotel saying he'd been banned for life.

    Recently, Burchill visited the hotel to apologize in person, in hope of making amends with the woman who had to clean the seagull-and-pepperoni-trashed room, but was told she was no longer there.

    “When I was talking to the people at the desk and the manager, they did say that they had heard this story from a long-term employee that works there,” said Burchill, “I was just kind of in and out. I didn't     want to overstay my welcome.” So he apologized and was forgiven. Burchill left them a present of about a pound of Brothers Pepperoni as a peace offering. It seemed to have worked.