Trace gases in the atmosphere are not as abundant as nitrogen or oxygen are. However, they play a part in making Earth's atmosphere one in which life can live. What do trace gases do in Earth's atmosphere?
O A. create the greenhouse effect by adding additional carbon dioxide
OB. allow water vapor to remain in the atmosphere
C. trap solar energy before it escapes to help Insulate Earth
D. Suspend smoke and small particles in the atmosphere

Read this summary of a scientific theory: "cells are the most basic structural and functional units of life. all living organisms are made up of one or more cells. all cells that are alive in the world today came from pre-existing cells." which of the following would require this theory to be modified? -a.) a survey finds that a majority of people believe viruses carry out the basic processes of life. -b.) a prominent scientist says she feels strongly that one day the theory will be challenged by life on other planets. -c.) the dna of unicellular and multi-cellular organisms is shown to have many fundamental similarities. -d.) scientific observations show that microscopic organisms living in the deep ocean are not made up of cells.