Motorists _____ of speeding may be banned from driving for a year.

A dog ran in front of my mother’s car and she __________ stop very quickly.

 _______air pollution getting worse, the government needs to come up with some effective measures to deal with it. 

Radium salts，which have been found to ______ in bones，give rise to bone cancer.

As you _________ the tasks, cross them off your list so you may feel less pressure..