根据句意和首字母填写单词。

1. Students often make spelling m_____ in their compositions.

2. Can you say a c_____ sentence?

3. The teacher is very p_____ to the students.

4. The boy r_____ to answer the question.

5. Tina is a(n) h_____ child. Trust her.

带有直流电磁机构的接触器是否允许频繁操作？为什么？