结构在规定的时间内,在规定的条件下,完成预定功能的概率称为()。
A、安全度
B、安全性
C、可靠度
D、可靠性
参考答案:C
When we finally ______ to get all the work done, we were so exhausted that we simply felt like lying down and having a good sleep.
A.tried
B.managed
C.succeeded
D.attempted
离心泵启动后空载时间不能过长。