Above the tree line there is a zone that is generally called alpine tundra.
林木线上方有一个区域，通常被称为高山苔原。
2
This rapid zone of transition is called the upper timberline or tree line.
这种快速的过渡地带被称为“上树带线”或“林木线”。
3
To illustrate smarter manufacturing, this example tracks an automobile as it moves along an assembly line from work zone to work zone. The two important aspects of this scenario are to.