Answer:
Blank 1 : Methane
Blank 2: Carbon dioxide
Step-by-step explanation:
A rotting biomass would emit a huge proportion of methane. Microbes work on waste products and releases methane and other gases. Methane is the primary biogas obtained from a decaying biomass. Methane can be used as a source of fuel for both industrial and domestic purposes.
Burning of biomass would produce carbon dioxide to a large extent. Methane produced would fuel the burning process so as to release significant amount of carbon dioxide.