求解They ----- no sooner ------ home than it began to rain.

had no sooner done,get有两种过去分词,一个是get-got-got,一个是get-got-gotten,所以可以填gotten,也可以填reached,基本表“到达”就这两个词,arrive不行,因为arrive at 是固定搭配,而home是副词,所以前面不能加介词,也没有冠词。