1.   The new air conditioning system proved inadequate.

2.   The new system has proved to be a highly effective way of extending trading hours.

3.   These systems have proved capable of meeting the specified operational requirements on a variety of fires in different categories of combustibles.

4.   The new security systems have proved insufficient to safeguard against computer fraud.

5.   The new computer system has already proved its worth.

6.   The crisis came when the political system proved incapable of controlling either the competing elites or the alienated masses.

7.   Furthermore, in warmer climates where Haemonchus spp. are prevalent, this system can prove dangerous since this very pathogenic genus establishes in both sheep and cattle.

8.   Although each brother had his own jury at the first trial, the system proved unwieldy.

9.   A police official familiar with the neighborhood said on Tuesday that the alarm system could prove useful in giving residents an easy way to alert the police to crime.

10.   A new computer system has proved incapable of discovering which companies are not paying premiums, and payments to many pensioners have been delayed by administrative confusion.