Which blood vessel returns blood to the left atrium?
a. aorta
b. left and right pulmonary arteries
c. superior and inferior vena cava
d. left and right pulmonary veins

Solutions to environmental problems in europe must

Group control group #1 experimental group yes yes yes control group #2 no new drug orange juice bed rest no yes no yes ves which of the following is the best explanation of why a second control group was included in this experiment? o a. to provide the volunteers in the study with something to drink o b. to prove that the common cold cannot be cured c. to confuse anyone who is trying to steal their new drug and sell it as their own invention o d. to researchers conclude that results are related to the new drug and not to the orange juice submit e previous

Drag the tiles to the correct boxes to complete the pairs. not all tiles will be used. match each type of organism to a characteristic that describes it.