Inventions All Around Us
Every invention has a story. These stories often have a lesson to teach, too. Here are the stories of some everyday household inventions.
Canned Food and the Can Opener—Get It Right!
Peter Durand invented canned food in 1810, but there was a problem. Durand didn't have a good way to open the cans. In 1858, Ezra Warner invented a can opener. It used a piece of metal to cut and remove the top from the can, but it was difficult to use. Finally, in 1870, William Lyman added a wheel to the can opener. The metal went around the top of the can and removed it easily. Finally, people were able to open cans without a lot of work. Canned food was soon popular.
Frozen Food—A Little Good Luck Can Help!
Clarence Birdseye had the chance to go on a trip toe Arctic. When people there caught fish, they put the fish in a container (容器) of ice to freeze it quickly. When people cooked the fish later, it was still good! This gave Birdseye an idea. He thought people could also have this kind of food at home. In 1926, Birdseye invented frozen food. People were able to store food in freezers for a long time.
Air Conditioning—One Answer to Two Problems!
Printing companies make books, so they use a lot of paper. Sometimes, changes in the weather can hurt the paper. In 1902, Willis Carrier invented air conditioning to control the temperature inside his printing company. This saved the paper. People soon realized other benefits of air conditioning. They started to air condition their homes in the summer. Carrier's invention changed the world!
When was canned food invented?

A．In 1810.	B．In 1870.
C．In 1902.	D．In 1926.

After the trip to the Arctic, Clarence Birdseye invented ____________.

A．canned food	B．can openers
C．frozen food	D．air conditioning

Changes in weather _____________ in Willis Carrier's company.

A．helped to keep food

B．hurt printing paper

C．caused health problems

D．made rooms comfortable

47. According to the passage, which of the following may lead to inventions?

A．People's needs.	B．Public support.
C．Modern technology.	D．Practical suggestions.