问题补充:
By the year scientists a lot of research on AIDS.
A. had done
B. do
C. are doing
D. will have done
答案:
A. had done
B. do
C. are doing
(答案→)D. will have done
解析:可联系答.案.网客服索取。
时间:2020-06-09 00:38:29
By the year scientists a lot of research on AIDS.
A. had done
B. do
C. are doing
D. will have done
A. had done
B. do
C. are doing
(答案→)D. will have done
解析:可联系答.案.网客服索取。