这是短文 My Friend, Albert Einstein （我的朋友阿尔伯特•爱因斯坦）中的一句话。

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When his wife died he was deeply shaken, but insisted that now more than ever was the time to be working hard. I remember going to his house to work with him during that sad time. His face was haggard and grief-lined, but he put forth a great effort to concentrate. To help him, I steered the discussion away from routine matters into more difficult theoretical problems, and Einstein gradually became absorbed in the discussion. We kept at it for some two hours, and at the end his eyes were no longer sad. As I left, he thanked me with moving sincerity. “It was a fun,” he said. He had had a moment of surcease from grief, and then groping words expressed a deep emotion.

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网友犯了一个原则错误，导致你误解了expressed的词性，以致于你无法理解句子结构。

动词的ed形式如果是非谓语动词，那就是过去分词，而过去分词做非谓语成分为被动意义。本句中expressed后接宾语a deep emotion, 所以expressed在此为主动意义，那么就肯定不是非谓语成分。有二种分析：第一，分析为一般过去时态的并列谓语动词；第二，为省略了had的过去完成时作并列谓语动词。综合考虑，第二种理解更符合语境。即expressed为had expressed过去完成时作并列谓语，承前省略了had.

groping words为现在分词短语作第二个谓语动作的状语（时间？方式？）。