下列事实或名词与环境污染无关的是（ ）
A．臭氧空洞
B．酸雨
C．潮汐
D．光化学烟雾
答案：C
潮汐与环境污染无关。
With so many people ____ the Internet, it is difficult to see online movies at the same time.
A．surf
B．to surf
C．surfing
D．surfed
奥迪100发动机曲轴轴向间隙为（）mm
A.0.01—0.28
B.0.03—0.056
C.0.07—0.19
D.0.020—0.38
