Which of the following best illustrates an achievement of classical indian science?

a. an astronomer demonstrates that earth moves in relation to the sun.
b. a citizen of the united states elects representatives to make decisions.
c. a teacher demonstrates that gravity acts on all objects equally.
d. a daoist priest teaches a class on stress and relaxation at a local college.

A. I'm positive this is your answer, you may research it further if you want to double check but i'm really sure. :)

Explanation:

because the vietnam war was fought in an especially brutal and untraditional way

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: