自动扶梯的倾斜角α大于30°不大于35°时,额定速度不应超过()m/s。
A.0.50
B.0.60
C.0.70
D.0.80
参考答案:A
有浓度为a% 的酒精一满瓶共m升,每次倒出n升,再用水加满,一共倒了10次,则加了10次水后瓶中的酒精浓度是___________.
The Parkers bought a new house but ______ will need a lot of work before they can move in.
A.they
B.it
C.one
D.which