指示词有this, that, these, those等。注意以下4点：
      (1) this, these是时间或空间上的“近指”，可与here连用；that, those是时间或空间上的“远指”，可与there连用。
      (2) 指上文提到的事一般用that，有时也用this，指下文的事只能用this。
      (3) 打电话时，用this来介绍自己，用that来问对方，不用I或you。
      (4) this和that还可表示程度，意为“如此，那么”，相当于so，作状语。
            (1)—He was nearly drowned once.
              —When was ______?
            —_____was in 1998 when he was in middle school.
             A. that; It             B. this; This                C. this; It   
               D. that; This
      解析：指上文提到的事多用that；后空是强调结构的简略式，完整的句是It was in was in 1998 when he was inmiddle school that he was nearly drowned once.其中when he was in middle
      school是定语从句。答案是A。
      (2)Sometimes it was a bit boring to work there because there wasn’t always ______ much to do.