Why have gasoline powered cars not been entirely replaced by electric cars?
a. electric cars are less comfortable.
b. people don’t like the way electric cars look.
c. electric cars have a limited driving range.
d. gas cars are as fuel efficient as electric cars.

The answer is C. 
Electric cars have a limited driving range.

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years