— Do you often go swimming Sunday mornings?— Yes. Why not with me this Sunday? A. on go B

问题补充：

— Do you often go swimming Sunday mornings?

— Yes. Why not with me this Sunday?

A. on, go

B. in; to go

C. on; going

D. in going

答案：

(答案→)A. on, go

B. in; to go

C. on; going

D. in going

解析：介词on与Why not的用法。在某一天，或某天某段时间用介词on，Why not do sh.?指“为什么不做某事”，do前是省略to的不定式。故选择A。