Which contribution to the body of scientific knowledge is most recent?
a)the development of the lever
b)the confirmation of the double-helix structure of dna
c)the discovery of electricity
d)the theory of evolution

An uncovered pot of water lies out in the sun. which statements correctly describe what happens at the surface of the liquid water? 1. the vapor pressure remains constant regardless of the water temperature. 2. the vapor pressure is produced by water molecules that have evaporated. 3. the vapor pressure increases as the sun heats the water in the pot. 4. evaporation stops once the vapor pressure reaches a certain point. 5. evaporation and condensation both occur on the liquid’s surface.