Earth's rotations and revolutions
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
In the first URL, the YouTube video explains why earth has spring, summer, autumn and winter seasons. The second URL summarizes the key takeaway points.
Osmosis is the movement of water across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. Osmosis helps regulate the flow of water in and out of cells, which is crucial to their function.
This 32 minute long YouTube video investigates the water contamination problems in Tanzania, with specific focus on Dar Es Salaam.
This 11 minute long YouTube video describes the various causes and types of water pollutants.
This YouTube video investigates what water pollution is and some examples and effects of water pollution.