1、who.
the boy 【who 主语】 【everyone thought插入语】 【would be chosen as谓语 】the winner by the judges
2、who
,(【who主语】 ) 【was remembered fo谓语】r her love poems
3、who/whom
【(who/whom 宾语 )】【 I从句主语 】【worked with 谓语】in Washington,
这种情况下,可用who代替whom.
祝你学习进步,时时开心!O(∩_∩)O~~