intervalen.丘陵间低地intervaln.间隔；休息时间；(数学)区间；(音乐)音程interval reasoning区间推理interval solutions区间解interval estimator区间估计interval of events间隔interval S-model区间s型模型interval operation区间运算interval parameter区间参数interval extension区间扩张interval measuring时间测量Interval selection时间段选择