Necessity Is the Mother of Invention
Bicycle
Mt. Tambora, a ____ in Indonesia, exploded in 1815.
The ____ created a huge cloud of ash, so crops failed around the world.
As a result, people didn’t have enough food ____ eat.
Surprisingly, this ____ traveling difficult.
Why? In those days, people rode ____ but many horses were killed for food.
People needed a new way to travel, and Karl ____ Drais invented the first bicycle in Germany in 1817.
____ bicycle had two wooden wheels but no pedals.
How did it move without ____
Well, riders simply pushed ____ bicycle forward with their feet.
The present-day bicycle is the result of many inventors’ work in ____ 19th century.
Whiteout
Whiteout was invented by ____ Graham.
In 1956, Graham was working at a bank ____ Texas, USA.
At that time, people had to retype the whole page when ____ made even a small mistake.
Graham was a bad typist, so she ____ a solution.
One ____ Graham saw some window painters.
When they made a ____ they corrected it by simply painting over it.
The next day, she made ____ own white paint and used it to correct her typing mistakes.
Surprisingly, nobody ____
Soon, everybody at the bank began ____ it.
Webcam
The ____ webcam was invented to watch a coffee pot.
In 1991, Dr. Quentin Stafford-Fraser and Dr. ____ Jardetzky were working at a computer lab in England.
To work better, they ____ lots of coffee.
However, there was only ____ coffee machine in the building.
So, they had to make ____ disappointing trips to the empty coffee pot.
As ____ solution, the two researchers set up a camera in front of the coffee machine.
The camera took pictures of the coffee pot three ____ a minute.
With ____ software, all the researchers in the building could see the pictures on their local network.
____ more disappointing trips!