根据下列句子的意思及所给单词的首字母或汉语提示，写出各单词的正确 形式。每空限填一词。
1. Science is one of my favorite s_____. How about you?
2. — Could you give me some a_____ on how to learn English well?
— I'd be glad to.
3. Doctors w_____ us to wash our hands before meals to keep disease away.
4. The more we get together, the _____ (快乐) we will be.
5. So far, we've _____ (成功) in saving thousands of people in danger.