一、单词拼写。
结合语境，根据首字母或汉语提示用单词的适当形式填空。
1. The word has long been in common _________ (使用).
2. It’s well known that Zheng He’s ______ (航行) made the connections between East and West closer.
3. A _________ (指令) is an order to a computer to take some kind of action.
4. I was certain that love was quite enough to __________ (战胜) our differences.
