these are book and ruler 里面里的book和ruler 需要加s吗

these are book and ruler 里面里的book和ruler 需要加s吗 where( )her book and ruler?is和are选哪个?一定要是正确答案, My ruler ,notebook and English book are( )backpack.A in B to is my ruler and that his book is (.) These are( ) 我们的 book and book ruler的同属一类的单词是什么? 圈出不同类的单词,(1)ruler tea pencil eraser book A book,a pen,a ruler and an eraser___on the desk.请问是填is还是are these are my brother and sister 里的brother和 sister要加s吗 pencil case eraser pen book ruler Are these your ruler?的单数句是什么 连词成句：pen, book, ruler,a, I,my,need ,and,math,a