对于化学反应A(g)＋3B(g) 
3C(g)，下列措施既可加快反应速率，又可提高A的转化率的是( )
| A．使用催化剂 |
| B．增大A物质的浓度 |
| C．增大B物质的浓度 |
| D．减小C物质的浓度 |
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 |
What I need is_____ book that contains ______ABC of oil painting.
| A．a; 不填 | B．the; 不填 | C．the; an | D．a ; the |