Answer:
Explanation:
During a physical change, the arrangement of particles may change but the mass, number of atoms and number of molecules will stay the same. ... During a chemical change, the mass and number of atoms is conserved, but the number of molecules is not always the same. Chemical reactions involve large changes in energy.
An obligatory parasite is a parasite that can not complete its life cycle without exploiting a suitable host
B. Sunlight doesn't reach the bottom of lakes..
An enzyme works like a key to a lock. If it finds the right thing it can work.
Hope it helps.
