根据句义，用括号内所给词的适当形式填空。

1. I think traveling by train is more popular. Because it's much cheaper and far more ________ (enjoy).

2. Chocolate is usually the ________ (child) favorite food.

3. It rained ________ (heavy), so he didn't go to work yesterday.

4. Thank you very much for your ________ (invite). But I'm so sorry that I can't come to your party tomorrow.

5. After the terrible earthquake, hundreds of people were ________ (home).