Look, think and write. 根据图示补全对话。

1.

    She is _____  _____ her skipping rope.

2.

    A: _____ is it?    

    B: It's a pen.

    A: Where is it?    

    B: It's _____ the eraser.

  3.  

     — How many dogs are there _____ _____ _____ the house(房子)?

     — There are _____. 

 4.    

      Please put your book _____ your head.

5.

     — Where is Danny?

     — He is _____ the desk.

动作速度测定一般可采用50米跑、4秒冲刺跑等方法测定，两者都是测定动作速度的有效方法。