这些英语句子怎么改形式?

问题描述:

这些英语句子怎么改形式?

this is a piano(改复数)

that knife is short(改复数)

is it a spoon?(改复数)

are they old cooks?(改单数)

are  those girls new?(肯定句)

are these pencil-boxes old?(肯定句)


this is a piano(改复数)These are pianosthat knife is short(改复数)Those knives are shortis it a spoon?(改复数)Are they spoons?are they old cooks?(改单数)Is he / she an old cook?楼上朋友错了这...