我喜欢巧克力，但我只是偶尔吃。

I love chocolate, but I only eat it ___now ___and ___then.

我祖父喜欢偶尔讲讲他年轻时的故事。

My grandfather likes to tell stories about his youth ___now ___and ___then.

她喜欢偶尔读一本好的悬疑小说。

She enjoys reading a good mystery novel ___now ___and ___then.