[解析]
(1)D.根据前句"Back in the pioneer days, people grew their own food,caught their own fish,and collected their own water."可知说的是用水,结合选项,应说住在靠近河流的地方很容易获得生活用水.故选D.
(2)A.根据后句"When building many factories right next to rivers for the water's power to make machines work, some people choose to live near a river for working."可知说的是河边,结合选项,应说为什么人们现在住在河边?故选A.
(3)F.根据前句" They use the river to ship large goods, and some of them work at these factories where power factories provide electricity to homes and businesses."可知说的是运送货物,结合选项,应说运送货物上船的人也住在这条河附近.故选F.
(4)C.根据后句"Such waste causes water to smell bad and pollutes the crops (庄稼) we eat. Water and crops in polluted areas can make people very sick."可知说的是污水,结合选项,应说有些工厂把废物排入河流.故选C.
(5)G.根据后句"Rivers can provide jobs and fun activities in a beautiful place. However, those living by rivers should be willing to accept possible problems as well."可知说的是考虑好问题,结合选项,应说在决定住在哪里之前,人们应该考虑一下可能的风险.故选G.