半斤八兩much to choose between
班門弄斧show off one’s slight talent/skill before an expert
半途而廢to give up halfway;to leave something unfinished
飽經(jīng)滄桑having lived through many changes
杯弓蛇影be jittery;suffer from imaginary fears (lit. to see a bow reflected in a cup as a snake)
背井離鄉(xiāng)be forced to leave one’s home (for a remote place)
本末倒置confusing cause and effect;to reverse the primary and secondary tasks (lit. to invert root and branch)
必不可少absolutely necessary
閉門思過shut oneself up and ponder one’s mistakes
變化無常irregular;capricious