工业噪声按噪声性质分为（）噪声.
A.空气动力性、电磁性
B.空气动力性、脉冲
C.空气动力性、稳态
D.脉冲、稳态
参考答案：D
I don’t think Germany will win the World Cup three years from now.
A．after three years
B．the third year
C．in three years
D．three years later
