If our bodies are not strong, our spirit to do things will certainly be quite dull.and at the same time, we are lack of energy (ies) to study.diseases will only attack the weak, but not the strong.
如果我们的身体不强壮，我们做事的精神一定会十分迟钝。而且同时，我们也缺少足够的精力来读书。疾病只为侵击体弱的人而不是强壮的人。
Why are our bodies not strong?because we do not pay attention to exercise. for this reason, we students must often take different kinds (sorts) of exercise in the gym.
为什么我们的身体会不强壮呢？因为我们不注意运动。因此，我们学生必须时常在运动场做不同种类的运动。
Exercise helps us (to) strengthen our bodies and avoid disease. it also teaches us cooperation, for most exercise is played by team.
运动帮助我们强壮身体并避免疾病。它也教我们团队合作，因为大多数的运动都是团体运动。