What is the difference between a primary and secondary source? explain and give an example?

Of seawater increases with decrease in the temperature. therefore, the cold water sinks to the deeper layers at the bottom

The activity of the modern sample is 1.10 bq . how long does that measurement take?

Which of the following is a true statement? a. individuals evolve to have adaptations. b. individuals have adaptations that can change over time. c. individuals have traits that may or may not make them successful at reproduction. d. populations cant evolve, only individual organisms.