We eat mooncakes,___pumpkin pie.

not

如果填and就不要逗号。

全句是：On Mid-autumn Festival,we eat mooncakes,___pumpkin pie.

句意：在中秋节，我们吃月饼，不是吃南瓜派。

填and句意不对了。

and

instead of; rather than; besides;没有语境啊

as well as