. C. Complete the following sentences with a suitable preposition.
1. There's no reason _______ you to be so unhappy. Cheer up!
2. In your next letter, I want you to give me a full description _______some photos, too.
3. The earthquake that hit our town yesterday caused damage______
4. No matter how hard I try, I can't find the solution_________
5. James is really in need _______
6. Man is the biggest threat________​