In 2004, approxhnately 5 million cars and trucks were classified as flex-fuel, which means they could run on gasoline or ethanol. in 2016, that number increased to about 20 million. how many more cars and trucks were flex-fuel in 2016?

d

step-by-step explanation:

d

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.