我国PM2.5的平均浓度限制为多少微克/立方米?()
A.65
B.75
C.85
D.95
参考答案:B
He said that light ______much faster than sound.
A.has travelled
B.went
C.travels
D.travelled
—Would you mind if I turned on the radio and listened to some music?
—______. In fact, I also like to listen to music in my car.
A.No, you can’t
B.Yes, I do
C.No, go ahead
D.OK, no problem