1.   Although this is not the place to undertake a detailed introduction to the model, a brief sketch will none the less prove useful.

2.   But though the negative aspects of their relationship outweighed its benefits, their association had proved useful.

3.   Genes probably goes beyond most introductory courses and will also prove useful to advanced students.

4.   In this particular case thrombolytic therapy proved useful in dissolving the clot and maintaining vessel patency.

5.   Morphine and its related narcotics have proved extremely useful in their ability to control pain.

6.   Of the species whose vegetative propagation is rapid, the small plants forming a green lawn over the bottom prove most useful.

7.   One hundred and twenty-nine replies were received - a good response which has proved very useful.

8.   The dialogue proved extremely useful to Park.