地下水是陆地、湿地及地表水体生态系统的支撑者,是普遍而活跃的环境因子。
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通常情况下,敏感性和特异性都最接近真实值的方法被称为
Most scientific theories omit consciousness as a causative factor, but it is difficult to conceive of law and design, so obvious from the “beginning,” without it.
软件的维护是指改写一部分或全部程序,软件维护可细分以下几种:改正性维护、适应性维护、 和 。