广播电视英语短句 第 225 课：灌溉系统-5

The researchers note that only four percent of the cropland in sub-Saharan Africa is irrigated. 研究人员注意到仅有4%的撒哈拉以南非洲的农田灌溉过。

Using solar power to pump water has higher costs at first. 使用太阳能抽水最初成本很高。

But the study says it can be more economical in the long term than using fuels like gasoline, diesel or kerosene. 但是研究指出从长远来说，灌溉系统比使用燃料如汽油、柴油、煤油更经济。

And solar power is environmentally friendly. 另外，太阳能也环保。