请帮助解释红字部分

Task force members rated their agreement with draft consensus statements on a 9-point numerical scoring system, using a modified Delphi process and the RAND/University of California Los Angeles Appropriateness Method, with refinement and iteration over 2 sessions. Consensus was determined based on the distribution of ratings.Results. Despite a paucity of direct evidence, 74 draft guidance statements were developed by the task force and agreed upon with consensus to provide guidance for use of the COVID-19 vaccines in RMD patients and to offer recommendations regarding the use and timing of immunomodulatory therapies around the time of vaccination

工作组成员使用改进的德尔菲法和兰德/加州大学洛杉矶分校适当性方法，以9分数字计分系统，对草案的共识程度进行了分级，并在2次会议上进行了改进和迭代。共识是根据评级的分布确定的。尽管缺乏直接证据，但工作组制定了74份指导性声明草案，并达成共识，为RMD患者使用COVID-19疫苗提供指导，并就疫苗接种前后免疫调节疗法的使用和时机提出建议。

1、哪个英文字表示分校？

2、什么是适当性方法？

3、迭代是什么意思？

4、“共识是根据评级的分布确定的”是什么意思？