精品无码久久久久久国产_成人午夜在线视频一区_亚洲最大的av网站_亚洲欧美综合区自拍另类_91精品国产一区_日韩精品中文在线观看_一道本无吗dⅴd在线播放一区_国产精品旅馆在线_欧美午夜久久久_亚洲自拍在线观看_黑人精品xxx一区一二区_亚洲精品日韩久久久_在线视频一区二区_国产欧美久久一区二区_中文字幕精品在线视频_成人欧美在线观看

The most advanced technology is worthless if it doesn't serve the farmer's needs.

我們必須平衡能源供應(yīng)與環(huán)境保護。

Lock up your libraries if you like; but there is no gate, no lock, no bolt that you can set upon the freedom of my mind.

The city is a living thing, always changing, always the same.

科學中真正的回報是為比自身更偉大的事業(yè)做出貢獻。