锻炼身体怎么说?exercise 可数嘛 举例子说明

锻炼身体：do exercise有时候也可以说：keep fitexercise不可数时,用作一个整体的概念eg.exercise is good for the health .eg.exercise keeps you supple .不可数时表示在一些具体的意思上.eg.he has always been v...