White-collar crime can be particularly difficult to uncover.
With stocks facing their worst declines in decades, this year may be particularly difficult to predict.
It will be particularly difficult to deal with the US Congress.
"Meanwhile, the new charge of indirect incitement could be particularly difficult to frame.
One bugbear, however, is going to be particularly difficult to eradicate.
An emotive issue, children's privacy can be particularly difficult to enforce.
In a climate of intense distrust of government, it will be particularly difficult to persuade voters to approve new funding.
"It will always be particularly difficult to beat a strong team at its own game," he said.
Given that all of Mr. Barak's plans have been frozen by the Israeli-Palestinian crisis, that demand does not seem to be particularly difficult to meet.
The steel rotor in the German design turned out to be particularly difficult to make, but it could spin twice as fast, meaning it produced more fuel.
The process is, though, proving to be particularly difficult to emulate with any great efficiency.During photosynthesis two "half-reactions" take place.
