11.   Kahn and Lamb make it essential.

12.   Most recently, the World Wide Web has been called the killer app for the Internet, making it essential.

13.   That makes it essential for countries to cooperate with each other and even compromise their sovereignty sometimes.

14.   That made it essential to find a child who could express feelings non-verbally.

15.   That makes it essential to find ways, including technologically driven ways, to raise productivity growth, Minehan said.

16.   This makes awareness essential.

17.   Workers believe that managers have become too powerful to defeat and that international competition makes cooperation essential.

18.   But he warned that approaching elections in Israel and the United States make it essential to pick up the pace.

19.   He said the economic crisis in Asia has made it essential for companies to maximise their software resources and increase productivity through products such as Express Meter.

20.   Observers say these factors make it essential for Britain to keep Beijing abreast of developments in the European Union during its presidency.