s for the revision of grammarChapter 与unless的转换2.与do… andor you will do的相互转换3.时态特点:主将主祈使主现主情态从现(适当防备虚拟语气的特殊时态)其他条件连词:as long as in casechapter 21. 形容词修饰名词: a famous German medical school an old bla