true or false : the transcontinental railroad linked the northern United States to the south
false: linked it to the east to west
who explored the land west of the Mississippi River in 1804?
lewis and clark
a way of sending signals through thin wire
telegraph
George Eastman invented what?
camera
a terrible disease that killed millions of people
smallpoxs
a weak or killed form of a disease that is given to people
name one of the two men who invented the gasoline powered car
karl benz and Gottlieb
ben franklin was in charge of what ?
the postal service
leis latimer helped who invent the light bulb?
Thomas Edison
Jonas salk created what?
the polio vaccine `
this machine was created in 1831, helped cutting grain
reaper
Henry Ford made cars in what city?
Detroit
why was it difficult to deliver mail by wagon?
the weather made it hard to deliver mail and bandits tried to rob the wagon
why were cameras so popular ?
because it helped people remember their favorite memories
Gertrude Elion's medicine helped treat people with what two diseases?
leukemia and malaria
this mail service was set up in 1860, delivering mail up to 75 miles away
Pony Express
who flew the first airplane in 1903?
the Wright Brothers
who invented the telephone ?
Alexander Graham Bell
why were gas lamps not so good?
because they caused fires and did not produce much light
true or false: you can drink milk straight from the cow ?
false: it needs to be heated first to kill the germs
heating up milk to kill germs is called ?
pasteurization
who was Sacagawea ?
a native american who helped lewis and clark. she translated and kept peace
When a telegraph received signals in a serious of dots and dashes on paper
morse code
when was the cell phone invented ?
1979
what is Polio?
a disease that can damage a person's spinal cord