lookinf for 后面加宾语,此句中是looking for a book.其实which指代the book,而the book 才是后面looking for 的真正宾语是a book还是the book如果你只针对这句话的话，就是the book 是宾语但其实两者是一样的，原句的意思是：对方在looking for a book，针对对方找的这本书，我就会回答说：这就是你要找的那本书，所以变成了the book