Questions 18 to 20 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions. Now, listen to the passage.

What is the speaker’s field of study

A．The importance of function in the design of a building.
B．A number of modern American architects and the important elements in their work.
C．Three main elements that architect must think when designing a building and a famous architect.
D．The important characteristics of the designs of one specific architect.

A．It will be impossible for him to register.
B．It may still be possible to register if he gets a letter from the university financial officer.
C．He will make arrangements with the registrar after registration.
D．He can still register but he will have to wait until the registration of senior students is over.