他偶尔进城购买补给品。

He goes into town ___every ___so ___often to buy supplies.

朋友们偶尔来看望她陪伴她。

Friends visit her ___every ___so ___often to keep her company.

我偶尔犒劳自己看场电影，作为工作的调剂。

I treat myself to a movie ___every ___so ___often as a break from work.