1 “... the past 30 years. The Handbook of Environmental Engineering is a collection of methodologies that study...”

2 “...Over the past decade the world has seen the rise of the fascinating and diverse field currently...”

3 “...The past few years have seen the emergence of a growing, widespread desire in this country...”

4 “...The past few years have seen the emergence of a growing, widespread desire in this country...”

5 “... the enormous development of experimental as well as theoretical aspects of cellular reactions during the past...”