旁路式旋风除尘器的除尘效率较高,一般可达到()。
A.40至50
B.55至60
C.70至80
D.80至90
参考答案:D
-There was hardly anything left after the earthquake, ______?
-______. People had to rebuild their houses.[ ]
A. wasn't there, Yes
B. was there, No
C. wasn't there, No
D. was there, Yes
五凌公司具有多年调节性能的水库是()。