A characteristic of barred-headed geese in flight is that they often fly in a certain formation, usually the bird in the back flies behind the side of the previous bird, so there is a common "human" formation. Some researchers think that this formation can reduce air resistance and reduce energy consumption. However, opponents think that if it is to reduce drag, birds should choose a straight formation, because a flight that follows a flight can reduce it to the greatest extent. The air resistance that small followers need to overcome. Which of the following, if true, can best question the opponent ’s conclusion? ['During the flight, the leading geese will change positions with their rear companions from time to time, otherwise they are easily exhausted.', 'The bar-headed goose drifts away from its companion in front of it, although it can not minimize the air resistance, it can greatly reduce the physical energy consumption required for ascent.', 'The bar-headed goose will need to determine the direction when flying, so it will not always line up in the shape of a "human".', 'In speed skating competitions, athletes often advance in the shape of a "person". One athlete is ahead, the other three are close behind, and the latter three players benefit from the reduced resistance.']