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?

icies, _______ to insure that compulsory education is truly free, ________by the local government across China since the start of school on September 1

Thousands of people have to leave the village ____ they love deeply because of the pollution.

下列各句中，没有语病的一句是（ ）

The twins look the same， but they are really different.