many schools do not have, or are likely to have=many schools do not have, or many schools are likely to have，that's why not后面跟nor不跟or
nor和or/and一样是连词，that's why D选项后面跟了主语they，有两个独立的句子还是对的，因为nor是连词，且是并列连词！！
FANBOYS：for, and, nor, but, or, yet, so

默念：遇到FANBOYS for and nor but or yet so 的句子，拆开独立的看～ not不要遗漏。