A third type of mountain may be formed as a result of volcanic activity which occurs in regions of active fold mountain belts, such as in the Cascade Range of western North America.
第三种类型的山可能是由于火山活动形成的，一般发生在活动性褶皱带地区，如北美西部的喀斯喀特山脉。
2
Spinning down the hard disk and setting a reduced CPU speed setting can be performed for any time range when the CPU and disk activity is below a set threshold.
让硬盘停转并且降低CPU速度可以在CPU及磁盘活动低于设定阈值的任何时间范围内执行。
3
Young stars are usually excluded from planet searches because they have intense magnetic fields that generate a range of phenomena known collectively as stellar activity, including flares and spots.