Which topic is suitable for a comparison-and-contrast essay?
a. the gas mileage of american cars
b. the difficulty of increasing gas mileage
c. the average price of gasoline in europe
d. differences between gasoline motors and electric motors

What is the best way to improve the conclusion? add a sentence to the ending that summarizes the writer’s topic. add a sentence to the middle that reflects on the writer’s experiences. revise the final sentence to have a different tone. revise the first sentence to state a future goal.