根據句意，用適當的介詞完成下列句子。
1. I can’t think of the answer _____ the question.
2. Danny would love to go _____ an exciting trip.
3. The soldiers trekked _____ the forest.
4. I must work hard so that I can provide a better life _____ my family.
5. The dreams of Chinese teenagers are quite different _____ those of American teenagers.
