Questions 18～21 are based on the following conversation.

How many dollars does the woman have to pay for the metal shelf

A．began to think of becoming a writer at Harvard
B．had always been successful in his writing career
C．want to Harvard to learn to write plays
D．worked as a newspaper man before becoming a writer

A．Read part of the book.
B．Read only one chapter of the book.
C．Read another book.
D．Read the whole hook.