How is the production of mercury from burning coal an environmental hazard? a. high concentrations of mercury in the air leads to global warming. b. mercury in water systems is transformed through biological processes into a substance that is toxic to animals. c. mercury combines with other coal emissions in the air to produce ozone. d. all of the above

Asnail, elodea (aquatic plant), or both were added to the tubes and they were stoppered. tubes were placed under a grow light for 24 hours and the results recorded. the test tubes were then covered for 24 hours to produce a dark environment and the results recorded. which statement best explains the change in test tube d from the light setup to the dark setup.

Hey me with this one❤☺❤ how do you say that a cell also has a life span and death like an organism? give one example.

What pattern of migration do whales follow?