Two middle school students present two bottles of seawater sample collected from the deep sea by China's manned submersible Jiaolong on the Xiangyanghong-9 ship in Qingdao, east China's Shandong Province, July 16, 2012. China's manned submersible Jiaolong has successfully completed its program of deep sea dives, with a sixth and final dive to 7,000 meters in the Mariana Trench in the Pacific Ocean on June 30.