That's his pencil--box．（该为复数形式）

That's his pencil--box．（该为复数形式） That's a box变成复数形式 where is my pencil-box?(改为复数形式） Where is my pencil-box （改为复数形式） pencil-box的复数形式是什么? It's her pencil—box.(改为复数句子） 英语复数形式apple.box.pencil.class.baby.pencil It's a pencil box 复数改 That's an egg in the box改为复数形式 It's his pencil case.(改为复数） This is his pencil-box.改为复数句子怎么改? It isn't his pencil-box?改成复数