Researchers are conducting a study to determine the effects of vitamin d on the human body. the study involves providing pills that contain vitamin d to one group of human subjects and pills that do not contain the vitamin or other active ingredients to another group of people. the pills that do not contain vitamin d are

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Paint and solvents pose no potential hazard to human health. select the best answer from the choices provided t f

Suppose you use three different scale to weigh a bag of organges. one scale says the nag weighs 2.1 lb, and third says it weighs 2.1 lb. the actual weight of the bag of organges is 2.153 lb. which of the following best decribes these results?