说谎话，____大。害自己，害大家。

    I'm 1English boy. My name 2 Tom. I'm a student. My teacher3 Miss Green. I have a sister.4 name is Lily. We are 5 the same school.

    We have two good 6named Jenny and Danny. They7 from Canada. They 8in China now. They9 blond hair and blue eyes. They10 China. We are all happy.

穿着旱冰鞋的小孩用力推墙，会感到墙也在推他，使他后退。这表明物体间力的作用是____ ；用力弯锯条，锯条变弯了，这说明力可以改变物体的____ 。