How many rubbers are there on the desk?There is o____one

How many rubbers are there on the desk?There is o____one There are some rubbers under the desk how many books are there on the desk?怎么回答? how many _____(watch)are there on the desk how many () (box）are there on the desk. how many rulers are there on the desk There are many pens on the desk,which one is How many apples are there on the desk now?There aren't ____ How ( )(many) string is there on the desk?括号内填much 还是many _____ many books there are on the desk!填what还是how,重谢! How many books are there on the desk?分析一下句子结构好吗 怎样回答How many books are there on the desk.这个句子,拜托 急用.