At first the experiment went on well, but ______ problems we hadn’t expected turned up later and it failed.
| A．outstanding |
| B．curious |
| C．powerful |
| D．various |
.—Do you have a minute? I’ve got something to tell you.
—Ok, _________ you make it short.
| A．now that | B．if only |
| C．so long as | D．every time |
. My parents live in a small village. They always keep candles in the house __________ there is a power cut.
| A．if | B．unless |
| C．in case | D．so that |
.Many of them turned a deaf ear to his advice, __________ they knew it to be valuable.
| A．as if | B．now that |
| C．even though | D．so that |
. It is difficult for us to learn a lesson in life __________ we’ve actually had that lesson.
| A．until | B．after |
| C．since | D．when |
.__________ he had not hurt his leg, John would have won the race.
| A．If | B．Since |
| C．Though | D．When |