阅读下面短文, 在空白处填入一个恰当的单词或用括号内所给单词的适当形式填空。
Everyone should exercise. It's an important part of(stay) healthy.
There are many different kinds of exercise such as cycling, walking,(run) and swimming. You can(do) lots of them. However, first of all, you should do them for fun. It is important(enjoy) what you are doing.
you just begin to exercise, you must(know) the following things: if you aren't feeling well, it is best not to exercise.(make) sure you start off slowly.As you get stronger(更强壮), you are able to do more activities. As beginner, you should make a plan, two or three times a week for fifteen to twenty minutes each time. Before(exercise), you must take a few minutes to warm up(热身). It's good you. After two or three weeks you will be able to spend more time exercising. And you'll be on your way to being healthier(更健康).