Questions 19 to 22 are based on the conversation you have just heard.

A．People can talk with others during the trip.
B．It only takes 15 minutes to cross the river.
C．It’s much cheaper than traveling by car.
D．People can relax and enjoy the splendid views of the city.

A．Because people can do it anytime and anywhere.
B．Because laughter is better than a regular fitness program.
C．Because laughter is more effective than some medicines.
D．Because people don’t have to learn how to laugh.