营运单位必须制定并实施安全系统和部件的在役检查大纲,该大纲在()必须完成并可供国家核安全监管部门查阅。()
A、建造前
B、选址阶段
C、运行阶段
D、装料前
参考答案:D
接种单位在购买二类疫苗,不需要向所在地疾控机构报告。
Sam ________ some knowledge of the computer just by watching others working on it.[ ]
A. brought up
B. looked up
C. picked up
D. set up