I was on the highway when this car went past, followed by a police car. They _______ at least 150 kilometers an hour.
A. should have been driving
B. must have been driving
C. could have driven
D. would have driven
No one really knows exactly of when the first people arrived in we now know as California
A．where B．when C． what D．which
Traditionally, college students hold a graduation ceremony to encourage themselves when they are to _________ on their life journey.
A. set up B. set off C. set about D. set down
You should inspect the wheels regularly, and replace them ______ they cause you trouble.
A. while B. when C. before D. Until
He is always late for work, and yet nothing is ever said to him. I don't know how he___________ it.
A. cuts down B. gets away with
C. takes off D. turns up
Gun control is a topic ____________ Americans have discussed for a long time.
A. of which B. with which
C. about which D. into which
