The excess air required for the combustion of pulverised coal is of the order of about __________ percent.%!

The excess air required for the combustion of pulverised coal is of th

1.	The excess air required for the combustion of pulverised coal is of the order of about __________ percent.%!
A.	5
B.	15
C.	30
D.	45
Answer» C. 30