take up:拿起；开始从事；占据(时间,地方)
take on:承担；呈现；具有；流行；接纳；雇用；穿上but he must take ______ the responsibility of teaching Engish to at least one certail member of the family.填什么呢，都可以表示承担责任啊？take on the responsibility 承担责任答案呢，你填什么你······take on 啊