Question

either or是就近一致还是前一致

Answer 1

和or连接的那一个主语一致。
由or, either ... or, neither … nor, not only ... but also等连接的名词或代词作主语时，谓语在符合毗邻一致的原则，即要与邻近的主语相一致。例如：
One or two friends are coming this evening. 今天晚上有一两个朋友要来。
Neither I nor he is to blame. 我和他俩都不该受责备。
Either the principal or his assistants are to attend the meeting. 要么校长要么他的助手们得去参加会议。

Answer 2

确切的说，是与or连接的那个主语一致。
由连词or, neither…or, either…or, not only …also, nor等连接的并列主语，谓语动词的单复数形式按毗邻一致的原则，与贴近它的主语一致。
例如：Either you or he is no telling the truth. 不是你就是他没讲真话。
Not only the switches but also the old wiring has been changed. 不仅开关，连那些老化了电路都已经更换了。