25. ―Look! What a mistake! Why?
―Sorry, I on it.
A. don’t concentrate
B. hadn’t concentrated
C. haven’t been concentrating
D. wasn’t concentrating
网友回答
A. don’t concentrate
B. hadn’t concentrated
C. haven’t been concentrating
(答案→)D. wasn’t concentrating
解析:可联系答.案.网客服索取。