From the beginning, water has furnished供给 man with a source of food and a highway to travel upon. The first _______1_______ arose where water was a dominant element in the environment, a challenge to mans ingenuity. The Egyptians invented the 365-day calendar日历, 历法 ____2_____ the Niles annual flooding. The Babylonians, who were among the most famous law-makers in ancient times, invented laws __3____ water usage. Water inspired the Chinese to build a 1,000-___4____ canal, a complex system which, after nearly 2,500 years, remains still practically __5____ and still commands the astonishment of engineers.
But the _____6___ never found complete solutions to their water problems. The Yellow River is also known_____7_____ Chinas Sorrow it is so unpredictable and dangerous ____8____ in a single flood it has caused a million ____9____. Floods slowed the great civilization of the Indus River Valley, and inadequate drainage ruined ___10_____ its land. Today water dominates _____11____as it always has done. Its presence continues to __12_____ the location of his homes and cities; its violent variability can __13___man or his herds or his crops; its routes links him__14____ his fellows; its immense value may ____15____ to already dangerous political conflicts. There are many examples of this in our own time.