质量特性值在质量标准允许范围内的波动是由()原因引起的。
A.偶然性
B.系统性
C.异常性
D.相关性
参考答案:A
If I _______ plan to do anything I wanted to, I’d like to go to Tibet and travel through as much of it as possible.
A.would
B.could
C.had to
D.ought to
矿井安全监控信号,直流模拟量优先选用的是()。
A.1~5mA
B.4~20mA
C.10~20mA
D.20~30mA