请问这道关于时态的英语题目为什么选这个?
—Hi,John,Ihavenotseenyouforalongtime.What_______recently?—Carryingonsomeresearchonwil...
—Hi, John, I have not seen you for a long time. What _______ recently?
—Carrying on some research on wildlife.
A. have you been doing
B. have you done
C. were you doing
D. did you do
请问这道题为什么选A不选B? 展开
—Carrying on some research on wildlife.
A. have you been doing
B. have you done
C. were you doing
D. did you do
请问这道题为什么选A不选B? 展开
2个回答
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