The CD is on the desk.的复数形式怎么说?

The CD is on the desk.的复数形式怎么说? There is an apple on the desk.( 一般问句.复数形式) 1、There is a book on the desk.改为复数形式 2、There are some kites there is a box on the desk怎样修改为复数形式 Is the dictionary on the desk?改为复数句 The radio is on the desk改为复数句 It's a purple flower.(改为复数形式）The photo is (on the desk.)对划线部 There is a knife on the desk.改复数句 There is a computer game on the desk 改为复数 there is a book on the desk改为复数句 Is there a watch on the desk?改为复数句 there is a pen on the desk 变为复数