船舶人员职责可分为:()
①管理级,
②操作级,
③技术级,
④支持级。
A、①②③④
B、①②④
C、①③④
D、①②③
参考答案:B
It can't be a(n) _____ that four jewelry stores were robbed in one night. [ ]
A. accident
B. incident
C. chance
D. coincidence
发生弥散性血管内凝血的流产是
A.先兆流产B.难免流产C.稽留流产D.不全流产E.完全流产