(2013·淮安模拟)—I’m really depressed after so many failures. I can’t see any hope.—Cheer up! Behind every misfortune !
Good ways of doing things can help us save time, and _____ it’s necessary for us to find them.
Tom____ me your secret, but he meant no harm.
It’s really a great pity that the great writer died ____ his works unfinished.
It is hoped that there will be ____ time in the future when ____ man can defeat cancer.
Scientists warn us _____ the need to keep an eye ____ the greenhouse effect.