Sewage is the primary source of the first three types.
The primary source of the play was Raphael Holinshed's Chronicles.
Coal-burning power plants are the primary source of the main chemical, nitrogen oxide.
Generally, the executives said that accounting concerns were not the primary source of the industry's troubles.
British traders were the primary source of the drug in China.
No one has suggested that Cartwright was the primary source of the Stuxnet disclosures.
The primary source of the spread was the sharing of needles to inject opioid drugs.
The interest payments on those securities are the primary source of the Fed's profits.
The "just as" manoeuvre is breathtaking, put forward as though the primary source of the grievances no longer mattered.
"That's the primary source of the noise, so obviously, that would be the top recommendation if we could make it," Kardous said.
Its advocates claim that it will become the primary source of the world's heating fuel, electricity, road transport fuel (cellulosic ethanol) and aviation fuel (biokerosene).
