Answer:
Most countries have their lowest voting age to 18.
Earth has seasons primarily due to its tilt of roughly 23 degrees, since this allows for sunlight to hit the Earth in different ways as the Earth rotates around the Sun. The distance of this rotation remains fairly constant.
All of the choices given were invented before 1840 except for the zipper. The zipper was invented in 189. The correct answer is B.
C--Television is how most Americans became aware of the Civil Rights Movement.
Television brought the movement and the reaction of police officers into the living rooms of every American. It is easy to dismiss the writings of people you don't know but to see the evidence of abuse and inequality is harder to ignore.