Helen and I ______ good friends. We are in the same class.

The study of natural history is not something to be left to biologistsIn fact, their capacity _____ the time they can spend away from their offices is very limited

He sold me the car at a cheap price and included the radio ______.

I use a clock to wake me up because at six o’clock each morning the train comes by my house.

(2013·贵州模拟)Tom, clean up the broken glass　　　someone walks on it