there is a book和there is one book如题,什么时候用a/an 什么时候用one 呢

Where ther is a will,there ia a way there is a book和there is one book如题,什么时候用a/an 什么时候用one 呢 there is a key and a book There is a book .对a提问 is there a book on the desk? Is there a book in the desk? There is a book.改为复数形式 Is there a maths book in your There is a book no the there is a book 改成否定句 there is a book 提问数量 There is a interesting book.还是an interesting book? 英语问题Is there a book on the table?Yes ,there is .Is the book red There is a book that is on the deskThere is a book （that） is on the desk和There is a book on the desk里面的on the desk是不是做定语 用have has或者ther is there are 正确形式填空,快啊,1.what does mike（ 2.（ ）any books in the bookcase?3.my father（ ）a story-book.4.（ ）a story-book on the table5.（ ）any flowers in the vase?6.how many students（ ）in the cla There is a book on the desk(改成否定句和一般疑问句） 帮下忙啦 there is a book under the desk变一般疑问句和否定句 There is a book in the bag.变否定句和一般疑问句并回答