1.   A firewall provides more than real security-it often plays an important role as a security blanket for management.

2.   As on land, local topography plays an important role in affecting the distribution of organisms.

3.   At a crucial moment, the United States played an important supporting role.

4.   Biology played an important role in southern exploration, for many of the early explorers were sealers and whalers.

5.   Certainly, it plays a more important role in higher mammals than in lower ones.

6.   Climate plays an important role too in the preservation of organic remains.

7.   Cuban Americans play an important role in whether he carries Florida in the fall campaign.