如图所示,倾角为θ的斜面体C置于水平面上,B置于斜面上,通过细绳跨过光滑的定滑轮与A相连,连接B的一段细绳与斜面平行,A、B、C都处于静止状态。则A.B受到C的摩擦力一定不为零B.C受到水平面的摩擦力一定为零C.水平面对C的支持力与B、C的总重力大小相等D.若将细绳剪断,B物体依然静止在斜面上,水平面对C的摩擦力为零
He commanded that all the gates _____when it was getting dark in case thieves came in .
– When will the sports meeting be held? – It has been suggested the sports meeting ______ till the smog is not so severe.
(2013)If we a table earlier, we couldn’t be standing here in a queue.
If the dog hadn’t woken us, we wouldn’t have noticed the fire and it _____ to the house next door.
-I didn’t watch the program “Where are we going, Dad?” yesterday. -I _______, either, if my father hadn’t reminded me.