1.  A booming economy, low unemployment and years of peace have made it difficult to replenish the graying ranks of white supremacists.

2.  A committee of teachers has drawn up guidelines for schools on how to deal with difficult students.

3.  A composite building of steel plus concrete is extremely difficult to achieve in New York City.

4.  A degree of violence might also be sufficient to control certain types of behaviour for which conviction was difficult or unlikely.

5.  A delicate plant, the Pinot Noir is difficult to nurture through the freezing cold winters of Champagne.

6.  A difficult and unsatisfactory situation became more complex by the day.

7.  A fair comparison between the two firms is extremely difficult.

8.  A fresh blanket of snow makes it difficult to see exactly how wide a swath the Merced and its feeder creeks cut.

9.  A heavy coat makes heat dissipation difficult.

10.  A large house is difficult to keep clean.