I cant really help you but here is a few articles that may help you.
http://www.icr.org/article/do-bacteria-evolve-resistance-antibiotics/
https://www.ncbi.nlm.nih.gov/books/NBK45713/
http://www.windows2universe.org/cool_stuff/tour_evolution_9.html
http://evolution.berkeley.edu/evolibrary/news/080401_mrsa
http://evolution.berkeley.edu/evolibrary/article/_0/evoscales_03
If you cut the cube and keep all the pieces you are causing only physical change
The answer is b because I learned this in 5th grade and I got it right
With water. PETE has a greater density than water where HDPE has a density less than water. Hope it helped:D