According to general relativity, why does earth orbit the sun? a. earth and the sun are continually exchanging photons of light in a way that holds earth in orbit. b. earth interacts with the magnetic field of the sun. c. matter contains quarks, and earth and sun attract each other with the "color force" between their quarks. d. the mass tied to the sun warps the space around it, in a similar fashion to a large mass at the center of the trampoline.

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.