45 Which of the following is NOT mentioned as one of the jobs of robots?
(A) To assemble automobiles.
(B) To work in dangerous places.
(C) To cook delicious meals.
(D) To explore the outer space.

Around forty years ago, there was a cartoon show on television called The Jetsons.

The Jetsons were a family of the future.

George Jetson went to work in a rocket火箭, and his wife Jane shopped for groceries on television.

The Jetsons had a housekeeper named Rosie. Rosie washed dishes and cleaned the floor, but she wasn’t an ordinary普通 housekeeper. Rosie was a robot.

At that time, some viewers thought the cartoon might predict預言 the real future.In some ways it did.

For example, some people shop on line now. But we don’t have robots as housekeepers. At least, not yet. Robots do various jobs today. They are often used in manufacturing製造業. They paint and assemble組裝 cars（Ａ） and put together electronic devices電子設備. Also, robots are used for jobs that are difficult or dangerous for humans. For instance例如, they were used to explore勘查 the planet Mars（Ｄ）, to investigate the inside of the great pyramids金字塔 in Egypt, and to search the wreckage殘骸 of earthquakes（Ｂ）.

There ARE robots that can do housework. Several vacuum cleaning robots掃地機器人 are available.

However, not many people buy these products. Why not? The main reason is cost. These robots are expensive. Another reason is that robot cleaners don’t always do a good job. A third reason is power. Most of these robots use batteries for power, and the batteries do not last long without recharging.