世界饭店的发展可以分为()时期、()时期、()时期和()时期。
参考答案:古代客栈、豪华饭店、商业饭店、现代饭店
— Amazing! You _____ wear slippers at work.
— Don't you know it's a fashion? [ ]
A. might
B. should
C. could
D. would
为保证风机的经济运行,对轴流风机应使用大风量,在这种条件下风机耗功较小。