Pope gregory vii and the german emperor henry iv fought over the issue of
a. the church’s collection of tithes.
b. papal appointment of bishops.
c. secular appointment of bishops.
d. rule of the papal states.

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:

possible the invasion of room could have been avodiable but the people of rome were to stubboron and to wealthy the kingdoms saw them as a threat if they dialred it downa   bit ten i dont think they wouldnt failed   china was not iacvvdoaible they caused war to much and were out of hand therefor that must have happened india i dont really know it could of