The reasons can cum up to following aspects, negative influence of market economy, unhealthy thoughts in sociality, trend of iniquity and phenomenon of corruption, distempered physical education system, weakness of collegians themselves and so on.

其原因可概括為市場(chǎng)經(jīng)濟(jì)的負(fù)面消極影響日本公共厕所尿尿视频、社會(huì)不良思潮的滲透侵蝕亚洲欧美性视频、不正之風(fēng)和腐敗現(xiàn)象的影響、大學(xué)生體育教育機(jī)制的不健全又大又粗又爽的视频网站、當(dāng)代大學(xué)生自身存在的弱點(diǎn)等人人色人人插人人操。

Through the implementation of stubble to field operations,it can curb this unhealthy trend and will continue increase soil fertility, and create good conditions for agricultural production.

通過(guò)實(shí)施根茬還田作業(yè)，既可抑制這種不良勢(shì)頭欧美黄网站色视频免费人，又可不斷增加土壤肥力黄片al区一区二，為農(nóng)業(yè)生產(chǎn)創(chuàng)造良好條件。

The paper reviewed the host selection mechanisms and rules of xylophagous insects and their application foreground in forest health evaluation. According to the rule that some secondary xylophagous insects always accompany with trees which are sub-healthy or unhealthy, ideas of diagnosing and evaluating forest health betimes using xylophagous insects were posed. Mathematical models would be established based mainly on interactions between quantity of xylophagous insect populations and status of forest health, interspecific interactions (community structure, biodiversity) and environmental factors were also added as supplementary parameters, in order to quantitatively analyzing and comprehensively evaluating forest health and its developing trend.

本文綜述了蛀干昆蟲對(duì)寄主植物選擇機(jī)制和規(guī)律的國(guó)內(nèi)外研究進(jìn)展及其在森林健康評(píng)價(jià)中的應(yīng)用前景亚洲欧美色自拍偷拍，根據(jù)蛀干昆蟲中次期性種類總是與亞健康和衰弱林木相伴的規(guī)律，提出了利用蛀干昆蟲早期診斷和評(píng)價(jià)森林健康的思路亚洲女毛，以蛀干昆蟲種群數(shù)量與林木健康狀況的相互關(guān)系為主黄片操n，輔以物種間相互作用關(guān)系、環(huán)境因子等建立數(shù)學(xué)模型毛片无码全部免费，定量分析和綜合評(píng)價(jià)森林健康及其發(fā)展趨勢(shì)射射射操操操。