锅炉所以能不断地产生蒸汽，一方面由于炉内不断（），另一方面由于蒸发设备构成锅炉内（）。
参考答案：加热；水循环
词汇。
1. Hainan Island is in the ____ (南方的) part of China.
2. She couldn't ____ (接受) our invitation because she was too busy.
3. It's difficult for him to make a ____ (决定) now.
4. They were discussing the problems of western ____ (社会).
5. — Which is the most ____ (传统的) festival of China?
— Spring Festival.
现代医学所称的玫瑰糠疹相当于中医的（）
A.热疮
B.风瘙痒
C.风癣
D.桃花癣
E.风热疮
