Why was there tension between us and ussr

Because they both wanted to be better in everything. They had the race to space also they both had nuclear power

true and they are like rivals toward each other in the space race time, they both were very competative on who put the flag on the moon first.

Doesn't your school check for plagarism?

They made a checks and balance system to equal power within the branches. the "check" meant that one branch would watch one branch and "balance" them if they were too powerful. if you want more info on this, i would just google checks and balance system.