A.As long as I have traveled　B.Now that I have traveled so much
C.Much as I have traveled　D.As I have traveled so much
20.A good storyteller must be able to hold his listeners’ curiosity______he reaches the end of the story.
A.when　B.unless　C.after　D.until
21.—Dad，I’ve finished my assignment.
—Good，and______you play or watch TV，you mustn’t disturb me.
A.whenever　B.whether　C.whatever　D.no matter