1.   Eleven or twelve hours under the blankets presented no challenge at all to Uncle Charlie.

2.   Home shopping, video on-demand, or other services present similar challenges.

3.   The management of Disinfection Disinfection in normal practice presents a challenge to management.

4.   The new century presented challenges that visionaries thought the old forms could not meet.

5.   The varied strata of modern society present numerous challenges to surveillance.

6.   Everyday business language where the same words mean very different things for our main contacts -- the Partners -- presented a challenge for each of us to overcome.

7.   Nonetheless, the incongruence of rRNA-based phylogenies with molecular trees derived from elongation factors or DNA-dependent RNA polymerases presents a challenge to molecular evolutionists.

8.   Each patient presents a challenge that requires a specific strategy.

9.   So the teacher decides to present a challenge.

10.   It also presents a challenge with respect to access.