have done everything possible
Chinese idioms, Pinyin is zh ì y ǐ J ì NY ǐ, meaning to the extreme, can not be added. It comes from Zhuangzi's Qi Wu Lun.
Idiom explanation
To: to. Yi: modal particle. To the extreme.
The origin of Idioms
Chuang Tzu's theory of Qi Wu: "those who think that there are things before the beginning are all finished and can't be added."
have done everything possible
think back and forth without end - chóu chú bù jué
a good essay which has solid substance and beautiful sentences - xián huá pèi shí