为你解答. 1.自从他是个中学生,他就一直呆在北京. He has been staying in Beijing since he was a middle school student. 2.格林一家居住欧洲十年了. The Greens have been living in Europe for ten years. 3.自2000年以来, 我家乡的环境就改善了很多. The environment of my hometown has improved a lot since 2000.