文章中请用以下提示的短语: it is necessary to keep a balanced diet(保持均衡饮食是必须的);had better(最好);it is important to do regular exercises(经常锻炼是重要的);it is essential to keep high mood(保持好心情是关键);renew our spirits and release our stress(焕发精神,解除压力);be bound to keep healthy(必定会保持健康)