在一定温度下的定容密闭容器中,表明反应:A(g)+2B(g) C(g)+D(g)已达到平衡状态的是( )A. A、C、D的物质的量浓度相等 B. 混合气体的密度不再改变 C. 气体的总物质的量不再改变 D. v(B) = 2v(C)
—— Do you mind my opening the window? It’s a bit hot in here. —— ______ , as a matter of fact
It’s high time you had your hair cut ; it’s getting _______ .
My friend showed me round the town, ______ was very kind of him.
They use computers to keep the traffic _______ smoothly.
If you leave the club, you will not be_____back in .