下列词加es：
1) s/x/ch/sh结尾的词加es
如：class, box, watch, brush, fox, match, dish, glass,
2）“辅音+y”结尾的词,y改为i后,加es
如：city, country, study,
3)下列o结尾的词加es: tomato,potato,hero,zero,mango,negro,...望采纳，谢谢