1.The paper thinks practicing shooting should be focused on the back ring as the aiming point.
据此认为，进行篮球投篮练习时应以篮圈后沿作为瞄准点更为有利。
2.The Cause and Countermeasure of Uncompleted Burning of Fuel to Back Ring Forming on Precalciner Kiln
燃料不完全燃烧对预分解窑后结圈的形成影响与对策
3.the metal back ring is fixedly matched with the metal sheet;
所述金属背环与所述金属片固定配合；