什么是燃烍效率？
参考答案：
是指进入锅炉内燃烧的燃料实际放出的热量与理论上所能放出的热量之比。
根据首字母提示写出单词
1. Any helpful s_______ would be welcome.
2. Are you all c_______ now about what you have to do?
3. The r______ of the game are quite simple.
4. She is a tour guide, so she always 1_______ the way while visiting the Science Museum.
5. It's one o'clock now. You must be s_______! Could I get you something to eat?
生产间隔期
