根据汉语提示完成单词拼写:

1. We should not forget the _____. (过去)

2. There are _____(千) of students in our school.

3. We _____ (确实) enjoyed working on the farm.

4. There are four _____ (季节)in a year.

5. One of the _____ (旅游者)came form Australia.