Cuál es la principal diferencia entre la atmósfera terrestre que existía cuándo se originó la vida actual?

One of the methods used to reduce energy use is: a. energy efficiency c. energy conservation b. energy reservation d. energy holding select the best answer from the choices provided a b c d i know the answer is not option a

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

Cathy hypothesized that corn would not grow in mud. to test this hypothesis, she took corn kernels and placed 5 in mud, 3 in soil, and 2 in water. to her surprise, the kernels in the mud grew faster than the kernels in the soil. what error might have caused these unexpected results? a. wrong hypothesis b. not enough variables c. undefined control d. too many variables