it‘s hard to i----------- how they can improve English so quickly

it's hard to think it hard to do 和 i think it's hard to do 有什么区别 It’s really hard to tell you I’m It’s really hard to tell you I’m It’s really hard to tell you I’m I know It' s hard to say in one word I know It' s hard to say in one word i know that it's hard to understand it's hard to tell~ “It's hard to die. 为什么要说I find it hard to do而不说I find it's hard to do I find it hard to imagine与It's hard to imagine区别,为什么一个没有is,一个有is. It's hard to comments to me. 求翻译6. It’s hard for me to admit to myself when I’m wrong. It's hard for me to make a resolution to give up all I have. it's hard to make living It's hard to die怎么解释? It's hard to study English.