Suddenly it thundered and lightened, and then it began to rain heavily.

突然雷电大作，已而大雨倾盆。

We were just thinking of going for an outing, when it began to rain.

我们正想去郊游，怎奈突然下起雨来。

It began to rain suddenly that day. Fortunately, I had an umbrella with me.

那天突然下起雨来，可巧我带了把伞。

The skies grew dark and it began to rain.

天渐渐黑了，又开始下雨。

As soon as we got home, it began to rain.

我们一到家, 天就下雨了.

As soon as he got home, it began to rain.

他一到家就开始下雨了.

Hardly had we started when it began to rain.

我们刚出发，就开始下雨了。

It began to rain and we scurried for shelter.

下起雨来，我们急忙找地方躲避。

To make matters worse, it began to rain heavily.

更糟糕的是，开始下大雨。

We were picking apples, when it began to rain.

我们正在摘苹果，忽然天下雨了。