5x社区离线视频5xsq

　　每天新闻前时段的PBS经典科普节目，探索人类文明方方面面。 　　sonychen 强烈推荐 　　------------------------------------------- 　　One of the best PBS series,A weekly documentary series, each episode providing an in-depth look at a different subject of scientific research. Subjects examined by this show have included the cutting edge of theoretical physics, a return to the Chernobyl nuclear reactor, the long-term effect... (展开全部)