1.   Mossotti said that plain water, particularly flowing water, was probably the biggest single factor in architectural erosion.

2.   Towering over the green weeds and flowing water are stark, black stalks that used to be trees.

3.   Using sensitive instruments, the lanky technician calculated the rate of flowing water -- vital information for the operation of a hydro-electric plant.

4.   The fourth planet from the sun, Mars is considered the most Earthlike, with a thin atmosphere, polar caps and deep canyons carved by flowing water.