Margines of laws and regulations, characteristics of accounting; 会计信息由于法律法规的局限性;会计事物的特定性;
RT line was measured from cutting-line of lateral cortical margins of the cervical vertebra to outer cortical margines of Luschka's joints. RT线测量:上下椎体外缘的切线至钩突关节最外侧点垂直距离,即RT线。