what is essential is invisiable to the eye

what is essential is invisiable to the eye what is essential is invisible to the eye. What bird is essential to eating? sometimes the heart sees what is invisible to the eye? what is essential is invisible to the eyes这句话是不是有语法错误? What bird is essential to eating?swallow中文是什麼意思 It is essential that everyone ___ what to do. What is becoming essential in the course of economic globali Beauty is in the eye of the beholder,What is in the eye of t essential to this rather abstract process is the development From him to be reelected ,what is essential is not that his To make what is said above__,English is essential.A.possible