根据句意和所给中文写出句中所缺的单词。

1.—Where’s Mr. Green?

   —He has gone to attend an__________(国际) meeting.

2.  I write to my mother every week, __________(主要) on Sundays.

3. The heavy work ___________(影响) his health, so he looked much older.

4. Do you know the saying, “A friend in need is a friend __________(真正地).

5. It’s important to_____________（教育）the young students.

开关型稳压电源的得名原因，在于其调整管工作在开关状态。（）