The 13th 14th and 15th amendment to the constitution were undermined by all of the following except a) jim crow laws b) literacy test c) plessy v. ferguson d) brown v. board of education

D- Brown versus board of education (1954) struck down the separate but equal doctrine established in plessy versus Ferguson. Segregation of white and black children in the public schools of a state solely on the basis of race, denies to black children the equal protection of the laws guaranteed by the 14th amendment

Explanation:

a)scientists

explanation:

the national defense education act had two main goals. the first one was to provide personal that was oriented to defense, including scholars, engineering students and so on. the other goal was to provide financial assistance for the students who would be enrolling at colleges and universities in the 1960s.

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: