21.  In the past, the court has taken weeks to decide whether to consider simple cases, and often takes several years to consider complex ones, she said.

22.  It is also a social event, and as researchers have discovered, a very complex one, at times bordering on the perverse.

23.  On the contrary, he built his career on the mistrust of certainties and was rarely content with a simple answer when a complex one could be found. . . .

24.  Start with simple repairs and projects before advancing to the complex ones.

25.  The case for stopping most funds from using derivatives, even complex ones, as they see fit, is unconvincing.

26.  The film is a departure for the director in that it has both a star-studded cast and a narrative, albeit a complex one.

27.  The issue of contractor versus employee is a complex one under I.R.S. rules, but the essential test is whether the employer exercises control over the work.

28.  The question now, a far more complex one, concerned the simplicity of victory and how it was achieved.

29.  The problems range from simple single-digit exercises to more complex double-digit ones.

30.  The relationship is a complex one, the author rightly notes.