General Electric’s Visilog is being developed, hopefully, to permit a planned moon-probe rocket to make a soft landing on the moon’s surface.

A．A research assistant.
B．A writer.
C．An office clerk.
D．A student.

A．He wanted to have a filling replaced.
B．He came in for a dental check up.
C．He came in for some dental advice.
D．He needed to have a tooth pulled.