Which statement is true about the Earth’s oceans? a. They are all getting larger due to the movement of tectonic plates. b. They have changed over time. c. They have not changed in 4 billion years. d. They are all getting smaller due to the movement of tectonic plates. Please select the best answer from the choices provided A B C D

Air pollution is only caused by human activity, select the best answer from the choices provided ot of true or false

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents

Select the correct answer from each drop-down menu. in an experiment, dr. travis examined the effects of calcium intake on osteoporosis, a condition that causes an increased risk of bone fractures. the amount of calcium is variable. the risk of bone fractures .