A. A statement of purpose
Answer: density
Convection is the circular cycle of rising and falling of a liquid or gas as it becomes hotter or cooler. When a liquid or gas becomes hotter, its density decreases, which causes the substance to rise. After rising, the substance loses heat and becomes cooler, which increases its density. This causes the substance to fall or sink to the bottom.
Answer:
large rocks
Explanation:
How do I make my soil drain better for plants?
Adding lots of organic matter such as compost, farm manure, or shredded leaves to clayey soil will allow it to drain more easily and hold the right amounts of water and air for better plant growth and increased biological activity.
Algae produces a estimated 30-50 percent of the net global oxygen .