A see-saw (teeter-totter) is a advice that we … បន្តការអាន How does a see-saw work?
Neon is the name given to a colorless gas that is present in the atmosphere in a very small proportion-1/65,000th of the air. And a neon-light is the colored light produced when electricity passes through the gas in the bulb or tube with low pressure.
In a neon-light, a glass tubing is filled with neon gas. An electric current
Who doesn’t know that anything can rise … បន្តការអាន How does a hot-air balloon go up?
A bicycle is one of the commonest and most su … បន្តការអាន How does a bicycle work (move)?