What is there under the chair?
What is there at the door?
What is there on the table?/ (What are there on the table? если такой вопрос встречался в учебнике)
What is there in the bag? / (What are there in the bag? - если такой вопрос встречался в учебнике)
What is there in the book? / (What are there in the book?если такой вопрос встречался в учебнике)