How does Whitman express his own grief about Lincoln death?

In his poem "O Captain! My Captain!", Whitman refers to Abraham Lincoln, who was murdered. The two of them never met, but Whitman deeply admired the president and was devastated because of his death.

your answer is c) experiments with water vapor showed that elements combine in specific proportions.

in the quotation from passage, connie willis states that literature is a way for authors from the past to communicate with readers of today. we can read their stories, books, and other texts to learn lessons about life. willis refers to these lessons as messages “from beyond the grave.” willis has a favorable viewpoint about the timelessness of literature.