当额定速度大于4m/s时,耗能型缓冲器行程在任何情况下,最小不应小于()m。
A、0.42;
B、0.54;
C、0.63;
D、0.9
参考答案:B
Grandma was ill. That was why she __ upstairs last night. [ ]
A. was helped
B. was helping
C. helped
—_____ is the drink?
—It's 8 yuan.:[ ]
A. How soon
B. How often
C. How much
D. How long