Which process provides the initial energy to support all of the levels in the energy pyramid shown above?

Me the formula cacl2 represents the compound

Which greenhouse gas is emitted when burn fossil fuels for energy? a.nitrogen b.oxygen c.carbon dioxide d.helium

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen