Questions 17～20 are based on the following talk. You now have 20 seconds to read Questions 17～20.

What must all students show at enrolment

A．Harmful Changes in Human History.
B．Healthy Changes in Human History.
C．Some Firsts in Human History.
D．Process of Change.

A．They are all teenagers.
B．They are frequently pessimistic.
C．They are from any profession.
D．they never admit defeat.

A．A large house where stockbrokers live.
B．A place where jobbers and stock brokers meet, to buy and sell shares.
C．A house in London, where stockbrokers are paid commission by their clients.
D．A place where jobbers make a very large profit.