This is a book和This is a bag 和This is a pen和This is a pencil和This is a ruler 的复数咋写.还有This is a pencil-box 复数怎么写 快点我来不及了
问题描述：
This is a book和This is a bag 和This is a pen和This is a pencil和This is a ruler 的复数咋写.
还有This is a pencil-box 复数怎么写 快点我来不及了
答
these are books these are bags these are pens these are pencils these are rulers
答
These are books These are bags ............
答
These are books.
These are bags.
These are pens.
These are pencils.
These are rulers.
These are pencil-boxes.