If those are your options the answer is B.
Hope this helps! Have great day.
D.
Because they -choose- to move
The traditional economic system was based on the direct exchange of goods and services, for example: you give me a shirt that you have and I give you the shoes! So, from the options the best answer is: passing clothes down from older to younger brother.
The morril act established a land grant for legislature which was supposed to be used for financing education institution, which included the blacks as well.
To find their speeds, you have to make them per hour instead of c hours.
You would divide each by their times, so 
and 
Train A's speed turns out to be 80 mph and Train B's is 88 mph
train B is faster.
Idk why you got it "wrong," I can't see your work, but I'm pretty sure this is how you'd do it :))
