我偶尔在城里见到他。

I see him ___occasionally in town.

我偶尔会吃一块巧克力，但这相当罕见。

___Occasionally I'll have a piece of chocolate, but it's quite rare.

我将需要用电脑通过电子邮件联系我的朋友，偶尔听几张CD。

I will need to use the computer to contact my friend on E-Mail and ___occasionally listen to a couple of CDs.