Answer:
B and D
Explanation:
Since it says all carbon atoms have six electrons, we know that they only have six protons too. The carbon 13 and 14 means they have extra neutrons that increases their atomic mass.
Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells.
Biomes are typically defined<span> by their climate and dominant vegetation, including grassland, tundra, desert, tropical rainforest, and deciduous and coniferous forests.</span>