名词什么时候复数?像at our great sale就不用复数,at very good prices就要用复数,这是

we sell all our clothes at very good prices.为什么price 用复数? our clothes at very good prices 翻译 at our great sale come and buy your clothes at our great sale!和 at very good p at first +数词+名词复数 是什么意思? 名词前什么时候不用加冠词?复数就不用加吗? 英语名词单词复数形式什么时候用? 复数可数名词前什么时候用the? be good for our mind and body为什么不用复数 There are great （改变）in our city.change用不用复数 at our great sale 翻译短语 名词什么时候用单数什么时候用复数?名词的单复数由谁决定的?