如图所示,在密闭容器中,一边装有一定量的金属钠,一边装有一定量的氧化汞,同时加热容器的两部分,钠和氧化汞都完全反应后,恢复到原温度,容器内空气的成分仍不变。则钠和氧化汞的物质的量之比是
—— 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 .