Polish scientist who wrote On the Revolutions of the Heavenly Spheres

a) Johannes Kelper

b) Nicolaus Copernicus

c) Galileo Galilei

d) Isaac Newton

answer is a meeting of congress.

explanation:

hope my answer has you!

la segunda guerra mundial comenzó el 1 de septiembre de 1939 y terminó el 2 de septiembre de 1945. ¡espero que esto ayude!

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation:

i am pretty sure it is a