主谓一致or--eitherofyourparentscometoseeyourecently?--No,buttheyhavesaidthattheyboth,oratleastoneofthem,comingtoseemeinacoupleofdays.A.Have;areB.Have;isC.Has;isD.Has;are想知道答案为什

Question

主谓一致 or
--_____ either of your parents come to see you recently?
--No,but they have said that they both,or at least one of them,_____coming to see me in a couple of days.
A.Have;are B.Have;is
C.Has;is D.Has;are
想知道答案为什么是C而不是D
这里的or与as well as、with的用法有什么区别(例如：An iron and steal works,with some satellite factories, is to be built here.)
“ they both,or at least one of them,_____coming to see me in a couple of days .。”
不明白为什么这句子里的or不是像as well as一样，而是就近原则

Answer 1

有or的时候,谓语和or后面的一致
你的例句很特殊,iron and steal works中的and 使iron steal作为一个主语.就像knife and fork
（一副刀叉）,作为一个主语,后面用is而不用are.
其他的时候and后面谓语常为复数
as well as 同and
A with B形式中,谓语同A