Can you describe _____it happened?— Yes,I was riding on my bike_____ a car knocked me down from behind[ ]

Some researchers believe that there is no doubt______acure for AIDS will be found.

There’s too much noise outside. _________of us two can fall asleep.

If I were to have time, I to the theatre tomorrow evening.

Where is your father—He Hongkong. He Hongkong for three days.