——The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?——____ my students have a try?
______ the ancient Egyptians built the pyramids puzzled people for centuries.
______ I’m well again, I can go on with my work.
The government has to close those small factories to prevent the water of the river ______.
We should try our best to ______ those people after the disaster.
------We want someone to design the new art museum for us. ------______the young fellow have a try?