Heat stored in the clouds can drive them upwards into towering thunderheads.

云朵里的热量能够驱使他们上升成为雷电。

Next time. See those clouds? They look like thunderheads. I think we'd better head for the car.

下次吧。看到那些云了吗？它们看起来像是积雨云。我想我们最好回车上去。

Seeing me, he dipped away, woodpecker fashion, among the trees that rose like green thunderheads above the general level of the forest.

看到我，他以啄木鸟的方式潜入了树林中，这些树木像绿色的雷云一样耸立在森林的一般水平之上。

OK. after a few minutes' walk, Uh, where did you say those ducklings were? I can't see very clearly. No wonder! Look! That thunderhead is right overhead now.

那就走吧。呃，你说的那些小鸭子在哪里？我没办法看得很清楚。抬头看了天空, 难怪！看！积雨云现在就在我们正上空。