下列实验能获得成功的是( )
| A．将乙醛滴入银氨溶液中，加热煮沸制银镜 |
| B．苯与浓溴水反应制取溴苯 |
| C．向浓溴水中加几滴稀苯酚溶液观察沉淀 |
| D．1 mol·L－1CuSO4溶液2 mL和0．5 mol·L－1NaOH溶液4 mL混合后加入40%的乙醛溶液0．5 mL，加热煮沸观察沉淀的颜色 |
The CDs are on sale! Buy one and you get ______ completely free.
| A．other | B．others | C．one | D．ones ks |
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 |
The children loved their day trip, and they enjoyed the horse ride ______.
| A．most | B．more | C．less | D．little |
Progress______ so far very good and we are sure that the work will be finished on time.
| A．was | B．had been | C．has been | D．will be |