The president appoints a cabinet member, but the senate rejects this appointment. this is an example of which principle in action?  

checks and balances 
judicial review 
federalism 
popular sovereignty 

Checks and balances.

Explanation:

Congress put a check on the President's picks.

answer; people where able to travel across the u.s.a faster than any other mode of transportation,travel time was about a week,from coast to coast

the space race was a battle to make advanced technology to get to the moon and to get a better understanding of space.