A lot of trees and flowers are on ______ of the river and the number of them is growing ______.

Are the offices in front of the dining hall?一Yes. The dining hall is _____ the offices. [ ]

What happened?—They didn’t ____ each other and had a fighting.

To save the drowning child, the boy plunged into the icy water without hesitation, ____ his own safety.

Peter forgot to tell us when______.[ ]