问题
I find ________ hard ________ me to understand his painting.—It’s polite ________ you to say so. His painting is nothing.
A:it; for; of
B:that; of; for
C:that; for; for
D:it; of; of;
B:that; of; for
C:that; for; for
D:it; of; of;
正确答案是：
