常用的时间状语this morning， the whole morning， all day yesterday， from nine to ten last evening， when， while例如:We were watching TV from seven to nine last night.时间点可以用介词短语.副词或从句来表示。
6.---I’m sorry to have kept you waiting long.Never mind. I ____ here for only a few minutes.A. have been B. have come C. have arrived D. wai
