Passage 1
Questions 26 to 29 are based on the passage you have just heard.

A．He has some mental diseases.
B．He is physically handicapped.
C．He works at home.
D．He can’t move about without his wheelchair.

A．How to make a powerful rocket engine.
B．How to ensure the safety of the crew.
C．How to choose qualified crewmen for the trip.
D．How to enable the spacecraft break free of gravity.