The adverb is slowly, Because adverbs tell what kind, how or to what extent. The adverb slowly (usually, they end in ly) is describing HOW someone did something. EX. Jessie ran slowly across the field. It tells how jessie ran.
And adverbs describe a verb.
When the old women HEARD that her grandson WAS ARRESTED for robbery, she WAS SHOCKED.
You shouldn't go there ALONE.
It was Peter Vanderdonk, a descendant of a historian, who convinced the villagers to accept Rip Van Winkle's story. He said that everything Rip described about the time period he was coming from was true, and that there was no need to doubt his words. Thus, everyone believed Peter (as he was a successor of a learned man) and Rip was readmitted into his society.