Feature and mechanism of the social-economic system in poverty-stricken areas characterized by ecological frailties--Taken Longnan District as a case是什么意思_Feature and mechanism of the social-economic system in poverty-stricken areas characterized by ecological frailties--Taken Longnan District as a case在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句