It is difficult to decide.
It is difficult to decide which room to select.
It is difficult to decide at which point ritual became theatre.
It is difficult to decide on the status of expressions like "the Baptists," "Adventists," and "spiritists".
Without occasional authorial guidance, it is difficult to decide which ideas — and thus which thinkers — to root for.
Although those two-class classifiers provide a promising way to screen potentially effective siRNAs, it is difficult to decide the boundary between the two classes.
It is difficult to decide which is more aggravating: to get this message from a doctor's office or a financial institution.
Dick Cheney, the Republican vice-presidential candidate, thinks it is difficult to decide what is in our strategic interests (news article, Sept. 1).
It is difficult to decide which is the worst aspect of the Republicans' latest try at repealing Obamacare: the irresponsibility, the cruelty or the lies.
And there were so many awful performances that it is difficult to decide which one was most deserving of that inglorious title.
When applied to a wedge-shaped description of the properties of the interface, a very flexible treatment is obtained but it is difficult to decide how to choose the model parameters.
