I came upon a shack in an isolated hollow, four miles up a winding mountain road over the Potomac River in West Virginia.
最终我到了西弗吉尼亚州波托马克河附近，在蜿蜒山路上方四公里处发现了一个孤立的小洞穴。
2
Abstract: the rectifier rolls are hollow rolls and there are regular holes on the surface. The winding rectifier rolls are used to keep the velocity evenly and to disperse and perforate fiber.