No single woman could have done that,___?A could they B couldn't they C could she D couldn't she答案是C 这里面have不是复数嘛?为什么不用 A? Nobody has phoned while I was not in,___?A has he B haven't they C hasn't he D have they答案是D 这里为什么要用复数?而且为什么要用they 而不是he?