don't worry.the doctor said i should ____(锻炼)my knee every morning.

don't worry.the doctor said i should ____(锻炼)my knee every morning.
don't worry.the doctor said i should ____(锻炼)my knee every morning.

don't worry.the doctor said i should ____(锻炼)my knee every morning.
don't worry.the doctor said i should _exercise/practise/work out___(锻炼)my knee every morning.
希望能够帮到楼主

exercise

practice