以空气为输送介质的风机，为防止转子锈住抱死必须（）切换
A．定期
B．不固定
C．无所谓
D．没必要
参考答案：A
怎样消除豆乳的豆腥味？
在空白处填入适当的句子，使对话完整。
Secretary: Hello, can I help you?
Jane Black: Yes.小题1:___________________________________________________?
Secretary: May I ask who’s calling?
Jane Black: This is Jane Black.
Secretary:小题2: ________________________________________. I’m sorry, Alice is at a meeting right now. 小题3:________________________________?
Jane Black: 小题4: _____. Could you tell her that I’ll be free tomorrow?
Secretary: Sure. Bye.
Jane Black: 小题5: _____________________.
