When did the first mammals and birds appear? 500,000,000 years ago
200,000,000 years ago
100,000,000 years ago
50,000,000 years ago

Which units ate used to measure both velocity and speed? check all that apply

One of the reasons that stars are so large is because

Abiology teacher asks students to give examples of genetic variations that support the idea that changes in a population’s environment affect genetic variation. which is the least supportive example? a.changes in genetics in human populationsb.antibiotic resistance in bacteria populationsc.pesticide resistance in garden insectsd.changes in the color of the peppered moth population in england