These are my sketch-books.They are on the desk.怎么样两句并一句?

These are my sketch-books.They are on the desk.怎么样两句并一句? 改英语句子改否定句They are some books on the desk.改一般疑问句和否定句These boy 改为否定句 The math books are on the desk. The math books are on the desk.改为否定句 改为否定句,The math books are on the desk. Are the books on the desk?改为否定句 Where are these/those books?的回答不是They are on the desk吗? there are some books on the desk改为单数句 are,any ,books ,on,desk ,there.,the连词成句 There are some books on the desk.改为否定句 Are those books on the desk作为否定句 There are two books on the desk.改为否定句