采用可变配气相位的目的是（）。
A.提高充气效率
B.提高进气时间
C.减少污染
D.便于排气
参考答案：A
Even though he has lived in China for many years, Mark still can't ____ himself to the Chinese customs. [ ]
A. apply
B. admit
C. adapt
D. accept
什么是单芯软光缆，它有什么特点？
