—Why are you late today.Mary?—I’m sorry,Mr Li.My bike ________ on the way.
________, he does get annoyed with her sometimes.
There was an old man wandering about the corner _____ waiting for someone.
John couldn’t finish his words ______ something had struck his throat.
______was known to all,William had broken his promise ______ he would give us a rise.
Students shouldn’t be given so difficult a problem ______they can not work out.