you should do more exercises__,don't always sit at the desk busying doing your_exercises

1.此句错误,必须改成：
You should do more (exercise).Don't always sit at the desk (busy) doing your exercises.
2.翻译：你应当做更多的运动.不要总是坐在桌边,忙于做你的练习题.
3.
1）do exercise表示“做运动”时,exercise是不可数名词,所以不用复数形式.
2）后句为一个祈使句,主语为省略的you.sit为谓语,所以短语be busy doing sth只能做伴随状语.
但是busy是形容词,并非动词,所以可以直接用busy doing your exercises即可,因为形容词短语可以直接做状语,表示伴随的状态.