It is he frequently returns home late makes his parents concerned about him.
A. because; that
B. that; that
C. 不填; that
D. what; that
网友回答
A. because; that
(答案→)B. that; that
C. 不填; that
D. what; that
解析：选B。考查强调句型。句意: 是他经常回家很晚使他父母为他担心。被强调部分that he frequently returns home late为主语从句。