11.   Whenever possible well-filtered rain water should be used.

12.   Only purified water is used.

13.   He also wants to use the water to irrigate barren desert land.

14.   The new system will optimize the efficiency with which water is used.

15.   Then he reverted to using plain water.

16.   Water is used again and again.

17.   The brewery uses water from the Taihu, one of the lakes in China which is protected from pollution.

18.   Use the water sparingly and clean the carpet a small section at a time.

19.   Gastroduodenal flow of the luminal contnts was visualised using water as a contrast medium, with appropriate adjustment of the time constant weighting of the system.