这个确实是比较状语从句, 话说我如果这样写你就能看出来了
He spent twice as much time on this picture as (I spent ) on that one.
因为有省略的缘故, 所以不是很容易看出来, 牢记as..as...的这种用法即可‘不能省略介词，否则就意思一样了’ 这一点没懂He looks like his father后的like his mother，你要是少了介词，那意思就是：他看起来比他妈妈更象爸爸了。He looks more like his father than his mother looks like his father.第二句也一样