日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

On May 28, 2007, workers at the Gymnasium of Beijing University of Science and Technology were fixing ball-like light-gathering shades on the roof of the building.

Each shade contains up to 150 light-pipes that temporarily store the outdoor light and then shed it evenly on the gymnasium through diffusing devices.

The gym with daytime electricity-free lighting is the venue for the taekwondo competitions during the 2008 Olympic Games.