Please help with this science assignment

Which substance is a steroid? cholesterol fatty acid monosaccharide trans fat

Harry lives in a city, and he has a lung condition known as asthma. on certain days, harry has to stay inside because pollutants in the air make it difficult for him to breathe. which of these pollution sources are nonpoint sources that might bother harry if he goes outside? choose the two that apply.

How many grams of iron can be made from 16.5 grams of fe2o3