尼日尔植树运动进行中，中国也该学习啊The Sahel is the area of Africa that lies between the Sahara desert to the north and more fertile land to the south. The dry plains of the Sahel are mostly treeless. Yet in Niger, one of the nations along the Sahel, millions of trees are now growing.
Researchers have been studying the progress of a …
发表于 2016-8-2 14:15:54