Ответ:

Решение:

В тексте упражнения 5, структуры для дачи советов выделены ниже:

You should walk for thirty minutes three days a week.

Walk a bit longer every week, but you don't have to walk every day.

You should also go swimming and cycling...

Eat healthy food for energy...

...you have to take water with you...

You should sleep for eight hours a day.

Ответ: should, don't have to, have to, Eat (imperative).