come down 有落下,下降,倒塌,还有留传的意思,例如:Her temperature came down in the evening;她的体温突然下降了。come on 的意思就更广泛了,用的最多的就是 快点 开始 还有加油鼓励方面的意思,例如:There's a storm coming on. We'd better go home...
come down 落下,下降,倒塌,例如:Her temperature came down in the evening;她的体温突然下降了。come on快点, 开始, 加油。例如:There's a storm coming on. We'd better go home.暴风雨快来 了,我们最好回家吧!food 当食物讲时是不可数名词的...