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问题 选择题

水平抛出的物体，不计空气阻力，则(        )

A．在相等时间内，动量的变化相同

B．在任何时间内，动量的变化方向都在竖直方向

C．在任何时间内，动量对时间的变化率相同

D．在刚抛出的瞬间，动量对时间的变化率为零

答案

A B C

动量的变化； g的方向是竖直向下的，物体动量变化竖直向下；动量的变化率为

阅读理解

阅读理解。

     There is Liu Fei's room. It's a small but nice room. On the wall, there are two maps. One is a map

of China, the other is of the world. There's a desk in front of the window and on the desk there is a clock.

Near the clock there is a glass. There's some water in it. And there are two pencils, one pen and some

books on the desk too. There is a chair on the floor and under the chair there's a ball. Liu Fei often

studies in his room and he likes his room very much.

1. Li Fei's room is ______.

A. big and nice  

B. small and nice  

C. big and bad  

D. small and bad

2. There is some ______ in the glass.

A. milk

B. water

C. tea

D. orange

3. There are some books ______.

A. on the chair

B. on the desk  

C. on the floor

D. on the wall

4. What can you see on the wall of the room?

A. Two maps.

B. A clock.  

C. A chair.

D. A window.

5. Where is the pen?

A. On the floor.

B. In the desk.  

C. Under the chair.

D. On the desk.

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多项选择题

齿突骨折，正确的摄片体位是（）

A.颈椎斜位

B.颈椎过屈位

C.颈椎正侧位

D.高颈椎仰卧水平侧位

E.第1、2颈椎开口位
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