如图所示，竖直平面内的3/4圆弧形光滑轨道半径为R，A端与圆心O等高，AD为与水平方向成45°角的斜面，B端在O的正上方，一个可看成质点的小球在A点正上方由静止开始释放，自由下落至A点后进入圆形轨道并恰能到达B点。求：

（1）到达B点的速度大小；

（2）释放点距A点的竖直高度；

（3）小球落到斜面上C点时的速度大小。

如图所示，竖直平面内的3/4圆弧形光滑轨道半径为R，A端与圆心O等高，AD为与水平方向成45°角的斜面，B端在O的正上方，一个可看成质点的小球在A点正上方由静止开始释放，自由下落至A点后进入圆形轨道并恰能到达B点。求：

（1）到达B点的速度大小；

（2）释放点距A点的竖直高度；

（3）小球落到斜面上C点时的速度大小。

下列关于运动的分解的说法中不正确的是(　 )

A.初速度不为零的匀加速直线运动,可以分解成一个匀速直线运动与一个初速为零的匀加速直线运动

B.一个在平面上的曲线运动可以分解成两个直线运动

C.沿斜面向上的运动可以分解为一个水平方向的运动和一个竖直向上的运动

D.可以将斜向下速度为 9 m/s的运动分解成两个速度分别为3 m/s和5 m/s的匀速运动

.

第二节（共5小题；每小题2分，满分10分）     

     根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项多余的选项。注意：请将答案填写在答题纸表格里对应的题号上。

There is an English saying, "  71  ". Until recently, few people took the saying seriously. Now, however, doctors have begun to look into laughter and the effects it had on human body.   72  .

    Tests were carried out to study the effects of laughter on the body. People watched funny films while doctors checked their hearts, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise.   73   it also works several groups of muscles in the face, the stomach, and even the feet. If laughter exercises the body, it must be beneficial.

    Other tests have shown that laughter appears to be able to reduce the effect of pain on the body. In one experiment doctors produced pain in groups of students who listened to different radio programs. The group that tolerated(忍耐) the pain for the longest time was the group which listened to a funny program.    74  

      75   They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

A. Laughter can make one’s life longer.

B. As a result of these discoveries, some doctors in the United States now hold laughter clinics, in which they help to improve their patients’ condition by encouraging them to laugh.

C. The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemicals in the brain which diminish both stress and pain.

D. Laughter is the best medicine

E. They have found that laughter really can improve people's health

F. It increases blood pressure, the heart beating and breathing;

G. Although laughter can help cure the disease, doctors still can not put this theory into clinic practice.

书面表达（满分25分）
一个英文网站面向中学生征稿。请你写一篇英语稿件，介绍“中秋节”及这个节日里的主要活动。
写作要点：
它是中国传统节日之一；
家人团聚；
赏月、吃月饼；
还有旅游、访友等其他活动。
注意：1.词数100左右；
2.可以适当增加细节，以使行文连贯。
3.开头语已经为你写好，不计入总词数。
参考词汇：中秋节 the Mid-Autumn Festival   农历  lunar calendar 赏月 enjoy the full moon 
月饼 moon cake
The Mid-Autumn Festival
The Mid-Autumn Festival falls on the 15^th of the eighth month of our Chinese lunar calendar.