8．It　it 代替 the British government.

　　9．sooner　sooner 与 later 对应。

　　10．until　until 引导时间状语从句，意为"直到......为止"。

　　Ⅳ.完形填空

　　The amount of usable water has always been of great interest in the world. __1__ springs and streams sometimes means control, particularly in the __2__ areas like the desert. The control is possible even without possession of large areas of __3__ land. In the early days of the American West, gun fights were not __4__ for the water resources (资源). And laws had to be __5__ to protect the water rights of the __6__ and the use of the water resources accordingly.

　　__7__ is known to us all, there is not __8__ water in all places for everyone to use as much as he likes. Deciding on the __9__ of water that will be used in any particular period __10__ careful planning, so that people can manage and use water more __11__. Farmers have to change their use of or demand for water __12__ the water supply forecast (预报)．

The __13__ water supply forecast is based more on the water from the __14__ than from the below. Interest is __15__ in the ways to increase rainfall by man­made methods, and to get water from the winter snow on mountain __16__. With special equipment, some scientists are studying the ways in which the mountain snow can be