（I）
I. 根据下列各句句意及所给单词的首字母或汉语提示，写出各单词的正确形式。
1. Anything that drops falls towards the centre of the earth because of the pull of g______.
2. The company’s head office is in Beijing, but it has b______ all over the country.
3. In t______ it is possible; in practice it is not.
4. It is good to be ______ (好奇的) about the world around you.
5. The river is the ______ (边界线) between the two countries.
II. 用括号内所给单词的适当形式填空。
1. The newspaper has a very good ______ (analyse) of the political situation.
2. The ______ (discover) of oil on their land made the people rapidly rich.
