It is believed that a new kind of drug ______ by the scientists and they are hopeful that they will succeed in a few months.
—I’m thinking of the test tomorrow. I’m afraid I can’t pass the time. — ______ ! I’m sure you’ll make it.
—How long are you staying ? —I don’t know. ______ .
He made up his mind to devote his life ____ pollution _____ happily.
Many people ______ for the Party before liberation.
When we talk about the _____we not only mean the sun, he earth and the moon but also _____ That is too far away to be seen.