实验室应建立并保持评审()的程序。
A、法律诉讼
B、任何合同
C、客户要求、标书和合同
D、供方
参考答案:C
I don't think you should mention it at the beginning of the story, or it may ____ the shocking ending. [ ]
A. give out
B. give away
C. give up
D. give off
太阳活动对地球造成的影响有()①引起潮汐现象②干扰无线电短波通讯③产生“磁暴”现象④诱发降水量变化
A.①②③
B.①②④
C.②③④
D.①③④