Ever since the Renaissance, European artists had treated the outside edges of paintings as window frames.
【参考译文】文艺复兴以来，欧洲艺术家们一直将绘画作品的边缘当做窗框来处理。
Ever since the Renaissance, European artists had treated the outside edges of paintings as window frames.
【参考译文】文艺复兴以来，欧洲艺术家们一直将绘画作品的边缘当做窗框来处理。
