—Hurryup.Thebusiscoming.—Oh,no.Wemustn’tcrossthestreet

問題詳情：

— Hurry up. The bus is coming.

— Oh, no. We mustn’t cross the street ________ the traffic light is green.

A. after           B. while         C. since           D. until

【回答】

D

知識點：連詞

題型：選擇題