In terms of generating portable electricity which is better a primary cell or a secondary cell? Explain

Rotenone is an insecticide that is toxic

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.

Long term exposure to waves can cause sunburns and skin cancer.