要去除,否则有两个谓语动词.
Such people 【（thatwere） recommended by her】 were reliable
添上that就是定语从句,省略that were就是过去分词作后置定语,作用相当于定语从句.
祝你进步!理解请采纳!原句可不可以看成省略that的句子呢要么that were一起省略，要么一个都不省略。