I won't tell her the answer until she ___ on it for two hours.A.h_英语解答

I won't tell her the answer until she ___ on it for two hours.
A.had worked
B.has been working
C.will have worked
D.will have been working
thank you

人气：116 ℃　时间：2019-08-19 03:30:58

解答

B.has been working
until引导时间状语从句,用现在表将来,所以没必要用will
因为句子中有for two hours,所以用完成时