The Fitball Push Up is a great regression of the Knee Push Up if you lack the pelvic stability to perform the Knee Push Up. It works on strengthening your midline in order to be able to progress.
Zhijinghe River is the highest arch bridge in the world. The 294 metres high bridge in the Three Gorges region of China carries the Shanghai–Chongqing Expressway across the valley of the Zhijinghe River, a northern tributary of the Qingjiang River.