For which of these questions could a testable hypothesis be developed? Check all that apply. A. Are gases better than solids? B. Do different liquids freeze at the same rate? C. Do cookies taste better when they are baked in a gas oven or in an electric oven? D. Does temperature affect the strength of a magnet? E. Does the color of water affect how quickly it evaporates?

Testable hypotheses could be developed for questions  B,  D,  and  E .

The main problem with  A  and  C  is the word "better".  This is a rubber word.  It means different things to different people, and it can mean different things to the same person at different times.  It's always a matter of opinion, it has no unique units of measure, and there is no concrete way to measure it.  Not good for developing a testable hypothesis.