The fact has worried many scientists _____ the earth is becoming warmer and warmer these years. [ ]

Tom that parked the car here,as he is the only one with a car

The reason why I like Sandy is that he can always stay and find ways to handle it in the face of trouble.

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?

When the teacher came in , the students _______ about the film.