单词拼写。

1. One should always b________ his opinions on facts.

2. The teacher r________ all the students should finish the exercises before the class was over.

3. What a good c________ of Japanese he has!

4. He looks serious, but ________ (实际上) he is very kind.

5. She speaks ________ (流利的) though not very correct French.

6. The old man's ________ language (母语) is Chinese.

7. He walked along in the shadows, hoping no one would r_______ him.

（）和（）是衡量接收机对微弱信号接收能力的两种表示方法。