1、ch:
rich ,lunch , teach ,push,touchsuch, search ,sketch, much ,catch, which ,fetch, lach ,peach, approach
2、sh:
Spanish,Swedish,British ,cash ,flash ,bash ,hash ,lush ,mash ,frush ,flush ,rush ,pash ,nash ,tash ,wash ,tush ,mash ,mesh ,mush
3、s:
bus,news,mathematics,phonetics,physics
4、x:
box,apex ,box ,complex ,convex ,crucifix ,duplex