Our bodies rest and grow the most while we are asleep. Children who are tired usually need more sleep. Boys and girls who are eight or nine years old need ten hours of sleep every night. Along with growth, sleep is important for paying attention. They can focus better in class after having plenty of rest.
我们的身体在入睡时休息并成长得最多。疲倦的孩子通常需要更多的睡眠。八九岁的男孩和女孩每晚需要十个小时的睡眠。除了促进生长，睡眠对于集中注意力也很重要。有了充足的休息后，他们上课更能集中注意力。
To sleep well, fresh air is important. If we do not get enough fresh air, we may feel tired when we wake up. While in bed, we must not cover our heads. Our lungs need to receive enough fresh air. If we open our windows at night, we can have plenty of fresh air. In fact, cool air is better than warm air for deep sleep.
要想睡好，新鲜空气很重要。如果没有足够的新鲜空气，我们醒来时可能会感到疲倦。在床上，我们一定不要蒙住头。我们的肺需要吸入足够的新鲜空气。如果我们晚上打开窗户，就能获得充足的新鲜空气。实际上，凉爽的空气比温暖的空气更有助于深度睡眠。