I （）my homework,I guess I can't join you.A.don't finish B.didn't finishC.haven't finishedD.won't finish答案是选C,可我选的A,为什么?

I（ ）[do]my homework I have my homework I did my homework I=GU是什么意思I为电流（物理）I=GU是什么意思I为电流 I do my homework every day.(用now改写） I （ ）（ ）my homework ( ). my,do,too,i,homework(.,) when I finish () my homework I finished my homework this afternoon.(对my homework 提问）. I do my homework on Sunday.对（do my homework提问） I am doing my homework now.(对画线部分提问）画线部分是my homework I did my homework yesterday 划线did my homework I'm doing my homework.对doing my homework提问 After I finish_____（do）my homework.原因 I have just finished my homework.（变为疑问句） I do my homework（ )(介词）a pen I,homework,often,do,watch,my,and,TV（.） I have already finished my homework(改为否定句） I m doing my homework.（变问句）?