Which was a major cause for the entry of the united states into works war 1?

a. germany decision to resume unrestricted submarine warfare.

b. the desire to collect reparations.

c. germany's invasion of belgium.

d. russia's decision to leave the war.

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:

it proved indian land claims were unjustified.

c. had saved colonel cresap's family from attack by other native americans.