Environmental issue has been a common concern for the whole world, in recent years, we have witnessed global warming, desertification, sandstorm and extinction of rare species around the world.

• 环境问题已经引起了全世界的关注,在近几年,我们见证了全球气候变暖、沙漠化、沙尘暴及珍稀物种灭绝。