When he was opening the door, he was that he was being followed by a policeman.
A. conscious
B. casual
C. careful
D. doubtful
网友回答
(答案→)A. conscious
B. casual
C. careful
D. doubtful
解析：词义辨析. A.意识到的;自觉的 B.随便的;临时的 C.认真的 D. 可疑的.句意:当他打开门,他意识到他被一个警察跟着.选A.