他深入调研，反复思量：“什么是‘好县’？”
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，详情可参考51吃瓜
* @param n 数组长度
2021—2025 年度，中国企业研发投入的区间分布保持稳定，延续了以亿元和千万元级企业为“腰部力量”、百亿元以上和千万元及以下企业作为“首”“尾”两端的基本态势。腰部区间覆盖了最大比例的企业数量，构成了研发梯队的中坚部分。
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