"He's always been extremely difficult to play.
The cultural issues have been extremely difficult to eradicate.
Thus, insights have been gained which otherwise would have been extremely difficult to obtain.
In bulk materials, however, it has been extremely difficult to achieve covalently bonded junctions between CNTs.
Even the President would acknowledge that it's been extremely difficult to fill the vacuum in Libya.
However, it has been extremely difficult to create solitons that are stable in three dimensions.
"If she was not there," Dr. Primas said, referring to Ms. Marker, "it would've been extremely difficult to diagnose".
"One of the points we all recognize is that it has been extremely difficult to integrate the third generation".
"Unfortunately it has been extremely difficult to have debate on a board which considers disagreement with management 'destructive,"' he wrote.
To Sam's great misfortune this has happened twice and on both occasions it has been extremely difficult to understand.
These regions, which encompass about 15percentt of the genome, have been extremely difficult to study using traditional methods.
