Fundamentally, the USPS is in a historic squeeze between technological change that has permanently decreased demand for its bread-and-butter product, first-class mail, and a regulatory structure that denies management the flexibility to adjust its operations to the new reality.
【例句解析】本句为简单句，句子主干为 the USPS is in a historic squeeze;between technological change and a regulatory structure 为介词短语做后置定语，用来修饰限定a historic squeeze，在between…and…短语内部，有两个that引导的定语从句，分别用来修饰限定 technological change和a regulatory structure;
【例句翻译】根本在于，美国邮局正处于一个历史性的挤压中：一方面是已经永久性的降低了其核心产品的需求的技术变革;另一方面是否认管理的灵活性去调整其业务以便适应新的现实的监管结构。
