Please choose the correct answer to the question: A student compared the speeds at which a large and a small marble rolled down an inclined plane. In order to make the findings more reliable, the student should

Answer1: release the marbles at different heights. Answer2: repeat the experiment several times. Answer3: tilt the plane at different angles. Answer4: use two marbles that are the same size.

Answer format: answer1/answer2/answer3/answer4