螺杆泵靠两根或几根相互啮合的螺杆间（）变化输送液体的。
A、容积
B、面积
C、体积
D、间隙
参考答案：A
—What did she______ you to do the day before yesterday?
—She ______ me to bring her watch here. [ ]
A. ask, ask
B. asked, asked
C. ask, asked
D. asked, ask
下述哪种疾病的特征影像是反S征（）
A.右上肺中央型肺癌
B.右下肺周围型肺癌
C.右下肺肺脓肿
D.左下叶背段结合球
E.左上肺错构瘤
