【问】 英语语法规定，含有since短语的句子或含有since从句的主句必须使用完成体，但是，下面的主句却使用了一般现在时。这是怎么回事呢?
 My life is entirely different since my divorce.
 【答】 按照英语语法的一般规则，在含有表时间的since从句和since介词短语的句子里，其主句通常使用完成体。但是，这条规则有某些例外。例如，当主句中含有静态意义的动词，特别是含有动词be和seem时，就可以使用非完成体形式，当be或seem的表语(主语补语)是个表时间的词语(ten weeks，two years)时尤其如此：
 1.Things are different since you have gone. (CGEL)
 自从你走以后情况变了。
 2. We are afraid to walk in the park since the woman was killed there.
 自从那个女人在公园里被杀之后，我们害怕在公园里散步。
 3. It seems a long time since we last met. (CGEL)
 自从我们上次见过面以来似乎过了很长时间。
 4. It's some considerable time since I have spoken to you on these matters. (Snow)
 自从我和你谈过这些事以来已经有不少时间了。
 5. It's a long time since I met you last. (Snow)
 我们已经分别很久了。
 6. It is just a week since we arrived here. (ALD)
 我们到这里刚一个星期。
 7. It was years since I had seen her. (Snow)
 自从我上次见过她已经有多年了。
 8. It is almost twenty years snice the war ended.
 战争结束以后差不多二十年了。
 9. It is a tong time since I saw you. (CGEL)
 打从我上次见过你已有很长时间了。
 当然，在上述情况下，仍然可以使用完成体：
 1. “My uncle comes in from Iran tonight. ”
 “How long has it been since you last saw him?”(TOEFL，74.1)
 “我叔叔今晚从伊朗回来了。”
 “你们分别后有多长时间了?”
 2. It's been ten years since they were last here. (CGEL)
 自从他们上次离开这儿已经有十年了。
 请做下面的英语试题：
 1. It's ages ____him.
 A. that I don't see B. that I didn't see
 C. ago I saw D. since I saw (Nelson，300D)
 2. ——What was the party like?
 ——Wonderful. It's years____I enjoyed myself so much，
 A. after B. when C. before D. since(全国高考英语试题，1993)