n double-blind studies neither the test subject or the researcher knows who was given the drug and who was given the control. Why are these studies effective for testing a drug that may elevate mood and relieve feelings of depression?

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Which ideas did your answer contain? check all that apply. no food for organisms no oxygen in the atmosphere no trees or flowering plants no products based on trees or plants (building materials, medicines, fuels, fibers) no fossil fuels

You find a fossil that you are sure shows evidence of bipedalism. you know this because which of the following anatomical traits is present? a. thighbones that angle in toward the knees b. a narrow pelvis c. opposable hallux d. posterior position of the foramen magnum