CA6100A柴油机的第一道气环是（）
A、单面梯形桶面环
B、普通矩形断面环
C、梯形环
D、扭曲环
参考答案：A
She showed the visitors around the museum, the construction _____ had taken more than three years. [ ]
A. for which
B. with which
C. of which
D. to which
ADSL是如何将语音与数据分开的？
