The research group ____________ 15 members has made great achievements in recent years.
A．is made up of B．makes up C．made up of D．making up of
Mark was a student at this university from 2006 to 2011，________he studied very hard and was made Chairman of the Students’ Union.
A．during which time B．for which time C．during whose time D．by that time
Liu Xiang is believed _____ over $ 20 million in advertisements last year alone.
A．to earn B．have earned C．to have earned D．having earned
The _______ boy made the police and his family _______.
A．gone; puzzled B．missing; puzzled C．missing;puzzling D．lost; puzzling
Kathy ______ some French while she was away on a business trip in France.
A．picked up B．took up C．made up D．turned up
Scientists are convinced _____ the positive effect of laughter _____ physical and mental health.
A．of; at B．by; in C．of; on D．on; at
