两种气态烃组成的混合气体完全燃烧后所得到CO2和H2O的物质的量随混合烃总物质的量的变化如图所示。下列有关混合气体的说法正确的是
| A．该混合气体中一定含有乙烯 |
| B．该混合气体一定含有甲烷和乙炔 |
| C．在110℃条件下，该混合气体与氧气混合，总混合气燃烧前后体积不变 |
| D．若混合气体由CH4和C2H4组成，则其体积比为1∶3 |
—— Do you mind my opening the window? It’s a bit hot in here.
—— ______ , as a matter of fact
| A．Go ahead | B．Yes, my pleasure |
C．Yes, I do | D．Come on |
It’s high time you had your hair cut ; it’s getting _______ . 
| A．too much long | B．much too long |
C．long too much | D．too long much |
My friend showed me round the town, ______ was very kind of him. 
| A．which | B．that | C．where | D．it |
They use computers to keep the traffic _______ smoothly.
| A．being run | B．run | C．to run | D．running |
If you leave the club, you will not be_____back in .
| A．received | B．admitted | C．turned | D．moved |