溫室效應(yīng)造成極端氣候，中國這里發(fā)洪水，美國卻是干旱
Heat and drought are threatening some of America's most productive farmland. The Department of Agriculture says an early summer heat wave across the West has increased demand for water to save dry crops. But in many areas, water supplies are limited. Water is also needed to fight wildfires in wester…