对可逆反应4NH3(g)+5O2(g) 
4NO(g)+6H2O(g),下列叙述正确的是
| A．达到化学平衡时,4v正(O2)=5v逆(NO) |
B．若单位时间内生成xmolNO的同时,消耗 xmolNH3,则反应达到平衡状态 |
| C．达到化学平衡时,若增加容器体积,则正反应速率减小,逆反应速率增大 |
| D．化学反应速率关系是2v正(NH3)=3v正(H2O) |
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 |
Jenny nearly missed the flight______ doing too much shopping.
| A．as a result of | B．on top of | C．in front of | D．in need of |
The CDs are on sale! Buy one and you get ______ completely free. 
| A． | other | B． | others | C． | one | D． | ones |
I’m sure that your letter will get______ attention. They know you’re waiting for the reply. 
| A．continued | B．immediate | C．careful | D．general |
All the dishes in this menu, ______ otherwise stated, will serve two to three people. 
| A．as | B．if | C．though | D．unless |