这是定语从句,这里that或who或whom都可；因为是作宾语,作宾语时,口语一般省略关系代词
例如1 Mrs Chancery is the teacher that I like best. the teacher在这里作宾语 her也是宾语, 句意重复
2 The woman （）was John's wife.为什么填I spoke to her 不对? 因为 the women 是宾语 her也是宾语 句子还原 I spoke to the woman (that) was John's wife.
同理 也可把题一 还原试试,就知道了!