some students watch tv and do you exercise a week ,but most student watch tv every day

问题描述:

some students watch tv and do you exercise a week ,but most student watch tv every day

这是翻译还是改错?
改错:some students watch tv and do some exercise once a week ,but most of student watch tv every day.
翻译:一些学生一周看一次电视和做运动,但大多数学生每天看电视.