Directions: For each of the following unfinished sentences there are four choices marked A, B, C and D．Choose the one answer that best completes the sentence．
21. Although many measures ___, the world’s economy is still going down.
A. are taken B. have been taken C. were taken D. will be taken
22. The children went home from school, their lessons ___ for the day.
A. finishing B. finished C. had finished D. were finished
23.____ with provocative(煽动、挑衅的)activities aimed at splitting the motherland, we will not sit by and do nothing.
A. Face B. Faced C. Facing D. To face
