the grand canal was built to connect
the yellow sea and the east china sea.
the yangtze river and the east china sea.
the huang he river and the yangtze river.
the huang he river and the yellow sea.

judaism developed through the growth of a single nation of people

christianity developed through followers spreading the religion throughout the world.

explanation:

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: