Are humans r-strategist or k-strategist?

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

Why do we perceive objects as retaining their brightness under different lighting levels?

Which situation is an example of not doing work? lifting a couch throwing a baseball running up stairs carrying a box