根据句意和汉语注释，写出单词的正确形式。

1. Tim's brother is so _____ (care) that he often forgets to do his homework.

2. Those _____ (visit) will stay in our school for two days.

3. It's very important for us to keep _____ (save).

4. They were too tired to walk any _____  (far).

5. Mary can learn Japanese by _____ (she).