there are a flower on the desk英语怎么改错句子

There are a book and two rulers on the desk句子改错 is flower there on desk the a连词成句 改错 There are a pen and tow books on the desk. There are a book and two pencils on the desk.改错 改错 There are two pencil-box on the desk Let's play a ping-po There is a eraser on the desk改错 There is a English book on the desk 改错 there are a doll on the bed怎么改错句 there is a book in the desk 怎么改错 how many books are there on the desk?怎么回答? There( are )(a book)and (two pens)(on) the desk There are a pencil and two pens on the desk.