他偶尔去镇上购买补给品。

He went into town ___every ___so ___often to buy supplies.

我们应该偶尔享受小乐趣以保持生活平衡。

We should indulge in small pleasures ___every ___so ___often to maintain balance in life.

软件偶尔自动更新以修复安全漏洞。

The software updates automatically ___every ___so ___often to fix security vulnerabilities.