The marginal cost of SO2 and NOx reductions through 2015 are less than $450/ and $2,300/ton, respectively, in all four multi-emissions reduction scenarios.
SO2 and NOx reductions have marginal costs.
SO2 and NOx reductions have no marginal costs.
A man is going for a swim.
During this time of war, we are very conscious of saving every possible resource. I appreciated this large household helping in the war effort.
Reminding a computer server and Anti-virus.
Bradley was not a good student.
The two girls are in bed.
Taco Bell is good because of the cheap prices.