1. Why do things thrown upward fall down?
A. gravity ran out
B. friction causes them to fall
C. gravity makes things fall
D. the kinetic energy of things are used up
2. What class of lever is a crowbar?
A. first
B. second
C. third
D. Fourth
3. Which reduces friction?
A. making the surface cool
B. making the surface wide
C. making the surface rough
D. making thesurface smoother
4. Which of the following applied in the machine?
A. effort
B. fulcrum
C. lift
D. resistance
5. Which of the following materials convert electricity tolight energy?
A. fan
B. Refrigerator
C. Incandescent bulb
D. allof these​