As soon as his teacher begins lecturing, he begins to doze off, not intentionally but .
A. personally
B. randomly
C. habitually
D. unconditionally
网友回答
A. personally
B. randomly
(答案→)C. habitually
D. unconditionally
解析：考察副词词义辨析。A就个人而言；B胡乱地；C习惯地；惯常地；D无条件地；句意：老师一开始上课，他就开始打瞌睡，这不是有意地，这是他习惯如此。根据句意说明c 正确。