This rapidzone 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”。
2
Spain has achieved one of the most rapid increases in wealth in the euro zone, but it remains stuck with an unbalanced economy and low domestic productivity.
虽然西班牙如今已是欧洲经济增长势头最为迅猛的国家，却还是被经济的不平衡和生产力的落后所困扰。
3
Working steadily on one task over an extended time is a good sign that you were in the creative zone, while rapid shifting from task to task suggests distractedness.