There is a common belief among them _______ rubbish can and should be put into good use.
She thinks women have to do more than men do when they ______ for jobs or honors.
_______ many times, he finally understood it.
Ladies and gentlemen, please remain ________ until the plane has come to a complete stop.
He told us whether _________ a picnic was still under discussion.
--Has your teacher returned from America yet? --Yes, but he _______ here for only three days before his company sent him to Africa.