Simple. Air has mass. And if air has mass it also has weight. You can feel air when the wind blows. Or do an experiment. Weigh an empty container. Then pump it to a vacuum. Weigh it again. The difference is the weight of the air inside.
To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight.
Answer:
Explanation:
Trisodium citrate has the chemical formula of Na3C6H5O7. It is sometimes referred to simply as "sodium citrate", though sodium citrate can refer to any of the three sodium salts of citric acid. It possesses a saline, mildly tart flavor. It is mildly basic and can be used along with citric acid to make biologically compatible buffers
Sodium citrate is chiefly used as a food additive, usually for flavor or as a preservative. Its E number is E331. Sodium citrate is employed as a flavoring agent in certain varieties of club soda. It is common as an ingredient in bratwurst, and is also used in commercial ready-to-drink beverages and drink mixes, contributing a tart flavor. It is found in gelatin mix[clarification needed], ice cream, yogurt, jams, sweets, milk powder, processed cheeses, carbonated beverages, and wine[citation needed], amongst others.
Answer:
They teach you the purpose of condoms (or you learn the hard way.)
how to prevent stds
Explanation:
That's all I can think of.
Answer: D. Extinctions occur at higher rates during times of ecological stress when populations and species are poorly adapted.