Some hot stone
are found under the surface of the earth………………..
a) 10km
b) 15km
c) 20km
d) 25km
Fuel from
biogas is of types:
a) 2
b) 3
c) 4
d) 5
It is obtained
from the alcoholic fermentation of biomass………………..
a) ethane gas
b) methane gas
c) naphthalene gas
d) ethanol
