用括号中所给单词的适当形式填空。

1. The more careful you are,              _______ (few) mistakes you may make.

2. Her husband was not as _______ (friend) to them as her parents.

3. Maths is one of                                 ______ (important) subjects.

4. If you want to keep fit, you’d better eat more vegetables and ______ (little) meat.

5. The population of Tianjin is _______ (small) than that of Beijing.