The horses each other the first prize in the match.
| A．completed against; of | B．competed against; to |
| C．competed against; for | D．completed; to get |
—How long do you suppose it is ____ he? —No more than half a week.
| A．when | B．before | C．after | D．since |
___ China’s reform（改革）and opening up in fate 1978, its quick development has aroused worldwide attention.
| A．When | B．As | C．While | D．Since |
We were told that we should follow the main road ___ we reached the central railway station.
| A．whenever | B．until | C．while | D．wherever |
Scientists say it may be five or six years ___ it is possible to test this medicine on human patients.
| A．since | B．after | C．before | D．when |
Tom’s and Joan’s ____ came to London last week.
| A．father-in-law | B．fathers-in-law | C．fathers-in-laws | D．father-in-laws |