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.是什么意思_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.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句