Microbes in Human Welfare

Aquatic fern which is an excellent biofertilizer is
Match column I with column II and select the correct answer from the given codes. 
Column I Column II
A,Methanogens(i)BOD
B.Fermentors(ii)Methane rich fuel gas
C.Organic waste in water(iii)Production of methane
D.Biogas (iv)Large vessels for growing microbes 
BGA is chiefly used as fertilizer in
Statement 1 : Biocontrol refers to the use of biological methods for controlling plant diseases and pests.
Statement 2 : Use of biocontrol measures will greatly reduce our dependence on toxic chemicals and pesticides.
What is the significance of $$CO_{2}$$ in bakery industry