1 . In order to be eligible to play in playoffs, players ______ present for at least 50 percent of games for the team they are registered on.

A．may have been	B．must have been
C．could have been	D．should have been

2 . 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