During which period did many marine species become extinct, but reptilian and amphibian species started to flourish?
a. Cambrian
b. Carboniferous
c. Ordovician
d. Permian

Which of the following statements is true about women and minorities in early psychology? a. in the early 20th century, numerous graduate schools recruited women and minorities to study psychology. b. opportunities in higher education were limited for women and minorities in the early 20th century due to discrimination. c. despite some obstacles, there were numerous employment opportunities for women and minorities. d. women and minorities were often selected to do academic research in an effort to make the field more diverse.

Which features on mars point to the possibility of liquid water on the planet? impact craters with sharp rims volcanic cones with craters gullies and stream-like channels mountain ranges with faults

Oxygen and hydrogen gas are at the same temperature t.what is the ratio of kinetic energies of oxygen molecule and hydrogen molecule if oxygen is 16 times heavier than hydrogen.