坏疽胆囊炎并发胆囊穿孔,多发生在
A.颈上部B.峡部C.底部D.前部
参考答案:C
I hope that ____ I have been able to do does good to them all. [ ]
A. which
B. what
C. that
D. when
焦-片距增大一倍,X线胶片感光量相应()
A.增加1/Z倍
B.增加1/4倍
C.增加1/8倍
D.减少至1/2
E.减少至1/4