根據(jù)短文內(nèi)容，從方框中選擇適當?shù)倪x項完成短文。（有兩個選項是多余的）

   Today a lot of people work in offices．They __1__ most of their time indoors．In the evenings they usually watch TV or __2__ newspapers．In order to keep __3__ good health, they know they have to exercise．

    Exercising in important．Doctors __4__ it is good for us．It makes us strong．Children who often exercise are more alert（機靈）．This means they do better in tests and schoolwork than those who don’t __5__ exercise．

    There are many ways to exercise．You can walk, run, swim, skate, or play ball games．Make sure you do more exercise in sports __6__, you must like what you’re doing．Exercise enough, but not __7__．It’s best to exercise twice each week．Thirty minutes each time is enough．Try to exercise many __8__ of things that you feel right for you．

   You can exercise in gyms．There are a lot of equipments（儀器）there．The equipment will help exercise your arms, legs and __9__ parts of your body．Some people buy equipments for their homes．But it is expensive．

   Exercising may be __10__．But you can exercise  together with your friends in a gym．You can feel very happy．