英语改复数形式改这几个哈……1、It's a knife.2、He is an English teacher.3、I'm a studen.

英语改复数形式改这几个哈……1、It's a knife.2、He is an English teacher.3、I'm a studen. It's a pencil box 复数改 it's a ruler?改复数句 英语This怎么改复数形式?This's 并说原因 is it yellow 改成复数形式怎么改 It is an egg变为复数形式怎么改 How much is it?谁会改（改为复数形式） 复数形式怎么改例如what‘s this in Eglish she `s our teacher怎样改复数形式 what's this?It's window.改复数句 英语句子改复数形式His father is a teacher. we have pink bags for women.How much is it It’s $30.话中How much is it It’s $30是否需要改复数形式? it's an orange Jacket改复数句 It's a table .(改复数句） 句子改复数形式英语的句子怎么该成复数形式 英语复数It's a potato改为复数形式 这是我的兄弟,怎么改复数形式? 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）