15) ____ with the size of the whole earth,the highest mountain does not seem high at all.A) When compared B) While comparing C) Compare D) Comparing

问题描述:

15) ____ with the size of the whole earth,the highest mountain does not seem high at all.
A) When compared B) While comparing C) Compare D) Comparing

a
这句话的主语是mountain,它是被compare的,要用被动语态,所以bcd都不对,只有a是被动语态,里面省略了主语及be动词