Which of the following are formulations of the second law of
thermodynamics?

A. No system can convert energy from one form to another useful
form with 100% efficiency.

B. It isn't possible to transfer heat from an object at a higher
temperature to another object at a lower temperature unless work
is done.

C. Entropy of a system increases over time.

D. It's possible to change heat completely into work, with no other
change taking place.

An experiment is conducted to see if cats preferred skim milk or 2% milk. a cup of skim milkwas put out for 5 kittens and then measured how much the kittens drank over the course of aday. following a cup of 2% milk was purout for the skittens and then masured how much thekittens drank over the course of a day. the same kittens were used and the milk was served atthe same temperature. it was discovered that the cats liked the 2% milk more than the skimmilk. what is the dependent variable in this experiment?