竞选演讲要求()
A、底气要足
B、态度要城
C、语言要简
D、方法要奇
参考答案:A, B, C
So far this year we _____ a fall in house prices by between 5 and 10 percent. [ ]
A. saw
B. see
C. had seen
D. have seen
为了保证氨冷器的蒸发空间,其液面太低会导致换热效果()。
A.变好
B.不变
C.变差
D.无法判断