题目内容：

As is known,it was( )that resulted in the terrible accident.
the driver`s being careless OR the driver was so careless
哪个?为什么?

优质解答

the driver`s being careless
作主语.
译文：就所知,是司机的粗心造成了这次严重的事故.
强调句型,强调的是主语
而the driver was so careless是一个句子,不能放在这