互锁机构在合上开合螺母时，（）就不能接通。
A.横向进给
B.纵向进给
C.机动进给
D.手动进给
参考答案：C
In the maths examination,I was puzzled with the last question,__________ ,my ink ran out. [ ]
A. what's worse
B. to make matters worse
C. what's more
D. A and B
贮气囊的作用不包括下列哪项（）
A.可进行控制或辅助呼吸
B.可使气体加温
C.挤压呼吸囊可使萎缩肺膨胀
D.缓冲和防止高压气体对肺的损伤
E.便于观察病人呼吸频率、幅度和呼吸阻力
