两速式调速器的柴油发动机的（）转速由人工控制。
A.怠速
B.低速
C.中间
D.高速
参考答案：C
He kissed his wife and then ______ goodbye ______ her when he left home. [ ]
A. say, to
B. said, to
C. spoke, to
D. said, with
开放性气胸急诊处理原则是（）
A.清创缝合术
B.封闭胸壁创口
C.立即剖胸探查
D.呼吸机辅助呼吸
E.抗休克
