语法学习—名词:可数名词+不可数名词（填空）
以s/sh/ch/x结尾的单词：加es：box—（）bus--() watch---() brush--()
一般情况直接加s：dog--() book---() bag---()
辅+o：tomato---() potato---() hero---() 元+o 结尾的单词,直接加s:radio---() zoo--() studio--()
以f/fe结尾,该f/fe为v,再加es:leaf---() life---() knife---() wife---() thief--()
改y为i:再加es,元+y :直接加s:city---() country---() family---() boy---() key--()
特殊变化：man---() woman--() tooth---() goose---() foot---() child---() mouse---()
单复同形：sheep---（） deer---() fish--() chinese---() japanese---() swiss---()