In atoms, electrons surround the nucleus in a) random patterns. b) specific energy levels. c) orbits like the planets. d) a "plum pudding" type arrangement.

The organ that has two atria and one ventricle is the

Which of the following statements best characterizes changes to agriculture in the united states since 1900? a. increased mechanization has reduced the need for labor. b. increased mechanization has increased the need for water, thereby increasing the need for labor. increased mechanization has increased the use of land, thereby increasing the need for labor. d. increased mechanization has increased food production, thereby increasing the need for labor. select the best answer from the choices provided.

What is the amount of organic matter in all living organisms in a habitat called?