were there a piece of paper on the teacher's desk just now?中有何错误

were there a piece of paper on the teacher's desk just now?中有何错误
were there a piece of paper on the teacher's desk just now?中有何错误

were there a piece of paper on the teacher's desk just now?中有何错误
看到有人答错了,说一句,应该是was there

a piece of是单数 用was

were改成where

were改为was a piece of paper 是单数