根据句义完成句中已给出首字母的单词。

1. He walked s_______ so that his son could catch up with him.

2. Paris is capital of F        .

3. At that time my mother learned English by l         to the tape.

4. His teacher didn’t go home u________ all his students left school.

5. The two phones are both nice. I really don’t know which one is b____