Identify which type of source is being described. sources present original research, whereas sources summarize scientific information.

Are the earth's ocean floor and continents the same age geologically? why or why not?

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one

Why are current extinctions of concern to enviromentalists?