Which event did Kent State students protest in 1970? the bombing of Cambodia
the Christmas bombing campaign
the My Lai Massacre
Vietnamization

the bombing of Cambodia

Explanation:

Students around the country had already being protesting the Vietnam war which President Nixon had promised he would end. Instead, in 1870 he announced that the US would invade and begin bombing Cambodia in order to target the hideouts and headquarters of the Viet Cong.

This prompted students to protest around the country including Kent State University where the students got a bit out of hand by breaking windows and setting a building on fire. In an inexcusable display of violence, some National Guards who were called, opened fire on the students and killed 4 marking a dark day in US history.

a. competition with other nations.

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: