柴油机动力不足的现象是（）。
A、运转不均匀抖动
B、爬坡能力下降
C、有喘气游动现象
D、柴油消耗量大
参考答案：B
She doesn't like Mrs. Smith, so she always avoids ____ with her. [ ]
A. to leave alone
B. being left alone
C. to be left alone
D. being left behind
如果是三对刮板的凸轮式刮板流量计，则每转一圈，就会排出（）计量室体积的液体。
A.2个
B.4个
C.6个
D.8个
