The correct choice is d, the burning if fossil fuels because fossil fuels do a lot of harm to the world.
Answer:
Reproduction.
Explanation:
At the cellular level indicate that the living organisms are made up of the smallest building blocks called cell. It refer to unicellular organisms i.e organism with one cell.
At the cellular level, membranes; for the whole organism, the skin is Reproduction because a single parent cell divides into two cells (offsprings), two divides into four cells and so on. It is called cell division and cell reproduction because a single cell skin divides to produce many cells.
Matter can be broken down into two categories: pure substances<span> and </span>mixtures.Pure substances<span> are further broken down into elements and compounds. ... A chemical </span>substance<span> is composed of one type of atom or molecule. A </span>mixture<span> is composed of different types of atoms or molecules that are not chemically bonded</span>
When salt and sugar dissolve in water it is a physical change. The chemical makeup of the salt and sugar are not changed.
Physical change