An earthworm helps to break up soil so that the roots of plants may receive oxygen. This enriches the soil and provides food for other organisms. What do these characteristics describe about the earthworm? A. its community B. its ecosystem C. its habitat D. its niche

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