Answer:
1) Jason was a very sensible person. He acted very sensibly.
2) She quickly adjusted the fees. She adapted quickly to any situation.
3) He measured the floor exactly. They proved to be perfectly exact measurements.
4) The stillness of the the tomb was awful. The tomb was awfully still.
5) It was a dangerous lake to swim in. The man was dangerously drunk. The gas smelled dangerous.
6) She performed magnificently. It was a magnificently beautiful performance.