What two body systems work together when the body temperature lowers and then shivers to keep you warm?

What's the waste product of electrons and pyruvate combining in fermentation?  

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?

Australopithecus robustus was likely the longest-surviving species of australopithecine in south africa. it had: a. large molars, a big face, and a sagittal crest. b. a large body, large teeth, and a sagittal crest. c. a big brain, big teeth, and a big face. d. a big face, large teeth, and a large body