英语语法句子结构问题There is an apple on the desk.中,on the desk是状语,an

英语语法句子结构问题There is an apple on the desk.中,on the desk是状语,an there is an apple on the desk There is an apple on the desk. There is an apple on the desk改为--- --- --- --- there on the There is an apple on the desk.( 一般问句.复数形式) There is （an apple）on the desk.括号里提问 there is an apple on the desk.怎样变复数?地点用不用变复数? There is an apple on the desk 这句的主语是什么? there is not an apple on the desk 的同义句 1,There is an apple on the desk.[改写一般疑问句,并作回答] there ----------------- an eraser on the desk. There is a book on the desk.中的on the desk是状语还是后置定语