1. Today a very wide spectrum of biological scientists are needed, both to develop the biotechnology of the next millennium and to ensure the ---- of life in our planet.

2. If you want that post youd better apply quickly; the last day for ---- applications is Friday.

3. In this paper, I would like to report some of the results of an ---- study of two hundred London families.

4. Recent studies have shown that smokers are more ---- to common colds and flu than non-smokers.

5. For the present, the party is expected to put its differences aside and campaign ---- for a victory at the forthcoming elections.