公安工作主要是从军事和政治方面维护国家安全。 ( )
参考答案：错
仿照例句，将下列句子合并为含定语从句的复合句。
Example: I like these singers. They write their own music.
→ I like these singers who write their own music.
1. I like Maria. She is clever and friendly.
_____________________________________
2. Here is the key. You're looking for it.
3. This is the best movie. I have seen it.
4. Do you know the girl? She is making a telephone call.
5. Let's go to the new sports center. It has just opened in our town.
破碎作业的设备费约占选矿厂设备的（）%。
A．10-20%
B．20-30%
C．30-40%
