改变转速是有限的，一般提高转速时，不能超过额定转速的（）%。
A、5
B、10
C、15
D、20
参考答案：B
《中国药典》2005年版一部规定，广藿香药材中叶不得少于
A．3%
B．5%
C．15%
D．10%
E．20%
用单词的适当形式填空。
1. The old man has a serious ______ (ill).
2. Mr Chen is ______ (stress) out.
3. It's easy to stay ______ (health).
4. —I think our teacher is working hard. He teaches us ______ (good).
—Yes, but he hasn't come today. He doesn't feel ______ (well).
5. I don't like ______ (west) music.
