Is that the reason __________ at the meeting for his carelessness in his work? Actually we think he is a man who is hard ______ himself especially in work.

    A. that he explained to all；on       B. what he explained all; with

C. why he explained to all; at                     D. which he explained to all; to

Is that the reason __________ at the meeting for his carelessness in his work? Actually we think he is a man who is hard ______ himself especially in work.

A. that he explained to all；on　　　 B. what he explained all; with

C. why he explained to all; at　　　　　　　 D. which he explained to all; to

Is that the reason ________he explained to all at the meeting for his carelessness in his work?  Actually we think he is a man who is hard ________ himself especially in work.

Is that the reason ________he explained to all at the meeting for his carelessness in his work?  Actually we think he is a man who is hard ________ himself especially in work.

A．that; on           B．what; with         C．why; at           D．which; to