－I think students should be allowed homework with friends.
－I disagree. They talk instead of homework.
A. do, doing
B. to do, to do
C. to do, doing
D. doing, to do
网友回答
A. do, doing
B. to do, to do
(答案→)C. to do, doing
D. doing, to do
解析：be allowed to do sth，表示被允许做某事，而instead of 为介词后街动词现在分词形式，故选C