国有企业是推进国家现代化、保障人民共同利益的重要力量，是我们党和国家事业发展的重要物质基础和政治基础。改革开放以来，国有企业改革发展不断取得重大进展，为推动经济社会发展、保障和改善民生做出了重大贡献。但也要看到，国有企业仍然存在一些亟待解决的突出矛盾和问题。面向未来，国有企业面临日益激烈的国际竞争和转型升级的巨大挑战。为此，2015年9月13日，国务院印发《关于深化国有企业改革的指导意见》。要认真贯彻落实党中央、国务院战略决策，按照“四个全面”战略布局的要求，以经济建设为中心，坚持问题导向，继续推进国有企业改革，切实破除体制机制障碍，坚定不移做强做优做大国有企业。

结合材料，请运用“社会发展的规律”的相关知识，分析我国不断深化国有企业改革的原因。

    The guzheng is a traditional Chinese musical instrument. It belongs to the zither（齐特琴）family of string instruments. It is the parent of many musical instruments of some other countries.

    The guzheng should not be confused with the guqin, another ancient Chinese zither but without bridges. Now the guzheng is zither with movable bridges and usually 21 strings, although it can have from 15-25 strings. The guzheng's strings were formerly made of silk, though most players used metal strings by the 20^th century. Since the mid-20^th century most performers use steel strings. The guzheng has a large resonant cavity（共振腔）.

    The guzheng has existed since the Warring States Period and became especially popular during the Qin dynasty. The number of strings on the guzheng has always fluctuated. There were as few as 6 to as many as 23 strings during the Tang dynasty. The earliest record of the guzheng belonged to the historian Sima Qian. Until 1961, the common guzheng had 16 strings, although by the mid-20^th century 18-string guzheng were also in use. In 1961, Xu Zhenggao, together with Wang Xunzhi, introduced the first 21-string guzheng after two years of research and development. In 1960, they also invented the “S-shaped” left string rest, which was quickly adopted by all guzheng makers and is still used today. This curve allows for greater ease in tuning the strings and, combined with strings of different thickness, allows for greater resonance in both the deeper and the higher pitch（音调）ranges. The 21-string guzheng is the most commonly used one, but some traditional musicians still use the 16-string one.

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