b) A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins.
c) The supply of water to land or crops to help growth, typically by means of channels.
d) A substance which has a molecular structure built up chiefly or completely from a large number of similar units bonded together, e.g. many synthetic organic materials used as plastics and resins.
This is easy, CO2 is (Carbon Dioxide) a main cause of air pollution. We put it in the air every day when we drive cars or vehicles. And from wildfires and volcanoes, but they rarely erupt now.
Enzymes are not used up in a chemical reaction. Usually, the enzyme will “reset” and be ready to use in another reaction. This is due to the fact that enzymes are proteins, and their shape is what they use in a chemical reaction.
