"A" grew frequently difficult and even eccentric (section 16 is only four words long).

When one of those disappears it is frequently difficult for the show to achieve the same .

Making a signal which gave a precise order was frequently difficult for a captain or admiral who wanted to do something out of the ordinary.

This advance knowledge is frequently difficult to satisfy and, in any case, is an inefficient use of resources.

However, most of us have misplaced them on the road through this frequently difficult life.

There is no question that the decision to allow an injured athlete to return to play is frequently difficult.

It is frequently difficult to speak, for example, of the 'victims' of water pollution.

When such permits to harvest are abused, it is frequently difficult to police.

With retrospective studies, the temporal relationship is frequently difficult to assess.

It is frequently difficult for temporary residents to obtain local insurance cover at a reasonable price.