They had kept working for several weeks everything was in order.
| A．before | B．after | C．since | D．unless |
The headmaster who had the grand ceremony waved to the crowds with a smile .
| A．included | B．joined | C．introduced | D．attended |
When the market economy is introduced, many factories will not .
| A．live | B．last | C．survive | D．keep |
This is an illness that can total blindness if it is left untreated.
| A．result from | B．lead in | C．result in | D．leave behind |
Our chemistry teacher a better way of working out the problem this morning.
| A．caught up with | B．came up with |
| C．put up with | D．got on with |