This can be surprisingly difficult for good adults to keep straight.
It can be surprisingly difficult to describe how pain feels.
Finding out the girl's room number had been surprisingly difficult.
They were finding being constantly in each other's company surprisingly difficult.
It had been surprisingly difficult to secure an audience with the director.
Reliable travel information about the country was surprisingly difficult to find.
It is surprisingly difficult to decide on an ideal goal weight for any individual.
It's a lovely wall, but it was surprisingly difficult to fashion.
It is surprisingly difficult to be sure if this ever happened.
In the wee hours of the morning, it can be surprisingly difficult to find a place to eat.