这道题 I'm fourteen,my sister is sixteen.So I'm( ) her.选D two years younger than
题目中提到我14岁,我姐姐16岁,所以由意思可得 我比我姐姐年轻（小）两岁,即为D的答案.如果单从语法的角度来看,其实A B C都没错,但都不符合题目的意思,所以不选.
I was surprised that she could run ( )I could.这题我觉得应该选C as fast as
A错,因为as...as...之间不用比较级； B错,见到than一般都是比较级,所以也错；D选项so...as...一般用于否定的时候..所以不选.终上所述,