10.　　 The force that attracts objects in space towards each other, and on the earth pulls them towards the center of the planet is called ____________ (重力).

Exercise 2 根据句意, 用所给的词或词组的最恰当形式填空(注意有多余选项)

9.　　　　 The ECP ___________ (出版) weekly.

8.　　　　 As a parent, you should not ___________(鼓励) bad habits in a child.

7.　　　　 We must care about further ___________ (进展).

6.　　　　 It’s a _______ (谜) to me why they didn’t choose him.

5.　　　　 The news he s__________ around the town was not true.

4.　　　　 The firework e__________ in his hand.

3.　　　　 The a___________ over dinner was warm and friendly.

2.　　　　 Christian, Buddhist and Hindu are the main r_________ in the world.

1.　　　　 A __________ is scientific study of the sun, moon, stars, planets, ect.