21. The field research will take Joan and Paul about five months; it will be a long time _____ wemeet them again. (A). after (B). before (C). since (D). when

73. The author mentions his experience in Thailand to show that _________. (A). the English prefer to make long speeches (B). too many words are of no use (C). people from Thailand are quiet and shy by nature (D). even talk and silence can be culturally different