3. What did a letter signed by world-famous scientist Albert Einstein communicate to Franklin D. Roosevelt early in the war?

I think the letter was about the first atomic bomb.

Explanation:

''The Einstein–Szilárd letter was a letter written by Leó Szilárd and signed by Albert Einstein that was sent to the United States President Franklin D. Roosevelt on August 2, 1939. ... It prompted action by Roosevelt, which eventually resulted in the Manhattan Project developing the first atomic bombs.''

got the explanation from wikipedia, hope this helps.

pennsylvania pennsylvania colony was a proprietary colony founded when william penn was awarded a charter by king charles ii in 1681. he set up the colony as one of religious freedom. the government included a representative legislature with popularly elected officials. all taxpaying freemen could vote.

i hope this

b. great plains

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