急！！！请问下面这个句子我该怎么分析．

It=Driving,你在分析试试。

Driving a car takes less time than taking the bus.

than 是副词吧@_@

take time to do something和take time doing something是一个意思，作者前面用了to do，后面用doing读起来比较好听吧，其实是一样的效果。

可以这样分析：
it takes = it spends = it costs
可以改成下面这样：
it costs less time （省略了taking the train）than taking the bus。

其实两种都是对的。因为动词不定式和-ing都可以作主语。这里的It是形式主语，代替了to drive或driving。

上面的句子可分析为：
To drive takes less time than to take the bus.
或
Driving takes less time than taking the bus.