In the image above of an alveolus, which structure binds oxygen? a. a b. b c. c d. d

Which of the following is not a symptom of desertification? a) decrease in salt content of the soil b) lowering of the water table c) reduced surface water d) increased soil erosion e) loss of native vegetation

The “ecological footprint” left by a citizen of a developed nation is about four times larger than that left by a citizen of a developing nation. why is this the case?

Sequence how oxygen accumulated in the atmosphere and the effect it had on life by completing the flowchart