色多多在线观看播放-色多多在线观看高清免费-色多多在线观看视频-色多多在线看-欧美aaaaa性bbbbb小妇-欧美aaaav免费大片

Sustainability isn't an option; it's a necessity for survival.

Fiction allows us to tell truths that are too slippery for nonfiction.

能源的未來在于傳統化石能源與可再生能源的融合發展。

The only maxim of a free government ought to be to trust no man living with power to endanger the public liberty.

我對建筑中消失的概念很感興趣。