Well for starters, gravity keeps things down on Earth. Also, gravity applies its force on to cars to maintain stability by forcing the tires to make constant contact to the ground creating friction between the rubber and road surface allowing the car to be moved. I'm sure someone else has better ideas!
Because the air in their wings helps them fly
Answer:
Three machines that humans have created are the lever, the wheel, and the axle, and also a pulley. even though there's actually more. A lever is A rigid bar that is free to move around a fixed point, such as a screwdriver. The wheel and axle, everyone should know what that is and what it does, it lifts heavy objects, moves people quickly, and moves parts of a complex machine. Pulleys are used to lift things, pulleys can be used singly or with many pulleys working together in order to transport people or things. They can also be used to provide power from one shaft to another. ... Construction pulleys are used in order to lift and place heavy materials.
Answer: Interneurons.
These interneurons transmit impulses to other neurons and thus form a part of the reflux arc.
