which是什么意思_which的翻译_音标_读音_用法_例句_爱词霸在线词典 The protection and improvement of the human environment is a major issue which affects the well-being of peoples and economic development throughout the world, read the final declaration from this gathering, the first of a sequence which would lead to the Rio de Janeiro Earth Summit in 1992 and the World Development Summit in Johannesburg three years ago