根据我国国内船舶保安规则,为了保证船舶保安计划的有效实施,船舶应当每隔()针对标明的保安威胁进行一次保安演练。
A.1个月
B.3个月
C.6个月
D.1年
参考答案:B
-When you your homework?
-I had finished it before he back.[ ]
A. have, finished, came
B. have, finished, was coming
C. did, finish, came
D. did, finish, was coming
实现JIT生产的重要工具是()。
A、自动化机器
B、看板
C、时间测定
D、工作分析