Answer to the first question: C
Answer to the second question: Pennsylvania
The Manhattan project is when they were building nuclear weapons for wwii
Answer:
A. Airplane
Explanation:
Around 1918, Air delivery, became the new mode of transportation for mail, as it rendered railroad services unnecessary. During this period, the Post Office moved on the airplane bandwagon early, there by, offering air mail service in the early 1900s.
Hence, the 1900's technological invention which allowed the U.S. postal service to deliver the mail considerably faster than previous methods is AIRPLANE.
I believe the answer is China. Hope this helps
