Liquid water exists based on the molecular structure of the water, and the temperature of those molecules. Liquid water is water, H2O within a temperature range of 0-100 degrees Celsius. The H20 compounds cling to other H20 compounds due to gravity, and a large amount of H2O compound form molecules of water.
Answer: D.) enacting a federal aluminum-can bill
Explanation:
Quizlet flash cards say D as well.
It is useful for an ecologist to identify the keystone species in an ecosystem because the keystone species is important to maintaining the stability of an ecosystem, and any changes in the keystone species population shows that there is changes in ecosystem health.