. — Why was Professor Johnson unhappy those days?
— The only reason was the theory he stick to wrong.
A. that; proving
B. why; being proved
C. that; proved
D. why; was proved
网友回答
A. that; proving
B. why; being proved
(答案→)C. that; proved
D. why; was proved
解析：可联系答.案.网客服索取。