依次填入下列各句横线上的汉字，正确的一组是（ ）。
⑴实践、认识、再实践、再认识……以________无穷。
⑵他是被_____迫而跟随别人做坏事的。
⑶琳琳优美的演唱，贏得全场观众一片喝_______。
⑷瞧她那_____得意相，一定又有什么高兴事。
| A．至 协 采 副 |
| B．致 胁 彩 付 |
| C．至 胁 彩 副 |
| D．致 协 采 付 |
I toured the Great Wall，I was deeply impressed with the beautiful scenery．
| A．For the first time | B．At first |
| C．The first time | D．It was the first time |
He was about to leave the office for home _______someone knocked the door and asked for some help.
| A．until | B．while |
| C．as | D．when |
If you find yourself ______ no one will help you, please call me.
| A．which | B．when |
| C．where | D．what |
The government has taken some measures to solve the shortage of water, but it may be some time __ the situation improves.
| A．since | B．when. |
| C．unless. | D．before. |
— Why was it so noisy over there?
— The Twins were surrounded by their fans ____ they stepped out of the hall.
| A．until | B．the moment |
| C．in case | D．so that |