脊髓灰质炎后遗症患者使用矫形器的目的是A．延缓肌肉萎缩 B．促进肌肉力量恢复 C．有

在“用单摆测重力加速度”的实验中，为了减少实验误差，以下操作正确的是[ ]

A. 选取长度10cm左右的细绳作为摆线

B. 在摆球运动到最低点处开始计时

C. 若摆球n次经过最低点所用的时间为t,则单摆的周期为T=

D. 多次改变摆长l，测出不同摆长下摆球运动的周期T，可由T-l图像求出重力加速度g

某幼儿园有58名小朋友，其年龄（单位：周岁）的直方图如图所示，则小朋友年龄的众数为（）。

A.4

B.5

C.25

D.58

About twenty of us had been fortunate enough to receive invitations to a film-studio(影棚)to take part in a crowd-scene. Although our “act" would last only for a short time, we could see quite a number of interesting things.

We all stood at the far end of the studio as workmen prepared the scene, setting up trees at the edge of a winding path. Very soon, bright lights were turned on and the big movie-camera was wheeled into position. The director shouted something to the camera operator and then went to speak to the two famous actors nearby. Since it was hot in the studio, it came as a surprise to us to see one of the actors put on a heavy overcoat and start walking along the path. A big fan began blowing tiny white feathers down on him, and soon the trees were covered in “snow". Two more fans were turned on, and a "strong wind" blew through the trees. The picture looked so real that it made us feel cold.

The next scene was a complete contrast (对比). The way it was filmed was quite unusual. Pictures in front taken on an island in the Pacific were shown on a glass screen (幕). An actor and actress stood of the scene so that they looked as if they were at the water’s edge on an island. By a simple trick like this, palm trees(棕榈树), sandy beaches, and blue, clear skies had been brought into the studio!

Since it was our turn next, we were left wondering what scene would be prepared for us. For a full three minutes in our lives we would be experiencing the excitement of being film "stars"!

小题1:Who is the author?

A．A cameraman.

B．A film director.

C．A crowd-scene actor.

D．A workman for scene setting.小题2:What made the author feel cold?

A．The heavy snowfall.

B．The man-made scene.

C．The low temperature.

D．The film being shown.小题3: What would happen in the "three minutes" mentioned in the last paragraph?

A．A new scene would be filmed.

B．More stars would act in the film.

C．The author would leave the studio.

D．The next scene would be prepared.

货币创造乘数

备用冷油器的投入前注油门（）、油侧排空门开启，见油后（）。