Scientists are convinced _____ the positive effect of laughter _____ physical and mental health．
A．of; on B．by; in C．of; at D．on; at
What would have happened, as far as the river bank?
A．Bob had walked farther B．if Bob should walk farther
C．if Bob walked farther D．had Bob walked farther
Rather than on a crowded bus, he always prefers a bicycle．
A．ride; ride B．riding; ride C．ride; to ride D．to ride; riding
—Remember the first time we met?
—Sure．You__________ the novel Pride and Prejudice in the library．
A．had borrowed B．have borrowed C．were borrowing D．borrowed
I can think of many cases students obviously know a lot of English words and expressions but couldn’t write a good essay．
A．why B．which C．as D．where
The Iranian government is accused of some terror organizations in the Middle East by the United States, who can’t not produce firm evidences to prove it．
A．sponsoring B．providing C．offering D．supplying
