In which decade were the first laws important laws passed to decrease to water pollution?

During convection, less dense fluid rises and denser fluid sinks.

What are 3 reasons that natural selection occurs

Science which of the following is an example of a cyclic behavior that is seasonal? i think the answer is d, i just need to double check : ). a. running from predators. b. searching for water. c. hunting at night. d. migrating for warmth. ***