On a hot day, an endotherm may give off more heat by increasing blood flow to the surface of the body.  Eric went outside in the summer. He is more or less likely to give off heat than if it was winter?
more

Because richer nations use more fossil fuels, they also cause more air pollution and global warming than poorer nations do.  Amy is from the USA, where she used lots of fossil fuels. Andy is from a poor country where there are few fossil fuels to be used. The person who's country will contribute more to air pollution is Amy's or Andy's?
Amy's

Air pressure is less at higher elevations.  Marcus is climbing a mountain, and notices that it is easier to breathe than it was before. This is likely because Marcus is at a lower elevation or higher elevation?
lower elevation

The more curved the surface of a lens is, the more it refracts the light that passes through it.  If Mona is building a lens for looking at the stars and she wants to make sure it refracts less light then the one she previously built, will she need to make the surface more or less curved then the one before less or more?
less