Sentence examples for are difficult to know from inspiring English sources

Projections for the cost of such externalities are difficult to know because these risks have not been part of the conversation thus far about Corn Belt Miscanthus.

The particular infection profile [11], [13] of a given disease can vary with location, societal structure, habits, customs, etc. Whereas these are difficult to know beforehand, diseases preferentially attack the weakest members of a population, typically the young and the old [14], [15].

In such an artificial condition, in which cAMP levels rise to many fold higher than physiological levels, these cAMP effectors may change cilia physiology in ways that are difficult to know, thereby indirectly changing Gli2 localization.

It's difficult to know".

It's difficult to know any more.

It is difficult to know now.

"It's difficult to know what's going on".

It's difficult to know who would be less flattered.

It is difficult to know if Ardant is serious.

It can be difficult to know where to begin.

"It was difficult to know how to do that".