They became close friends, the best of each other due to their dependence on the very best when you travel. They are placed side by side, and the difficulty is when you force your mind to get the best.
They became each other's best friend. Because most have to rely on themselves when traveling. They are placed side by side on the difficulties encountered, and inspire each other to be the best.
They become the best friend of each other. Due to the need to rely on each other the most when departure. They will be side by side when facing the difficulty and the inner strength to each other as well.