Air pollution. Cleaner burning than other fossil fuels, the combustion of natural gas<span> produces negligible amounts of sulfur, mercury, and particulates. Burning</span>natural gas does<span> produce nitrogen oxides (NOx), which are precursors to smog, but at lower levels than gasoline and diesel used for motor vehicles.</span>
Epithelia are classified by the number of cell layers and the general shape of the cells
The answer is b, chloroplast.
B, Provide nutritional support to the embryo. It is not D, as the breasts are not part of the female reproductive system. It isn't C because during pregnancy, fetal and maternal blood do not mix. It also isn't D since women do not produce sperm.
Food molecules contain chemical energy which is released when its chemical bonds are broken.
Food undergoes digestion in the digestive system and is broken down into its monomer units. Carbohydrates, which are the principal source of energy, are broken down into glucose. Glucose is the monomer unit of carbohydrates.
Glucose then is taken up by cells and is used in cellular respiration, which involves three main stages namely glycolysis, Krebs cycle and the electron transport chain, through which a glucose molecule is processed to form at least 36 molecules of ATP.
ATP is the form of energy that cells use.