综合填空：用方框中所给单词的适当形式填空，使短文正确、通顺。
| or put try back time every against chair easily relax |
Looking after your back If you want to have a strong healthy back, you should have good posture (姿势).
You should put the least stress (压力) on your 1______. If you have good posture, you won't get tired
2______ you won't get pain in your back；you will look good!
When you are sitting down,
★ 3______ to keep your back straight.
★Don't cross your legs.
★Put your back 4______ the back of the chair.
If you are working on a computer,
★Sit back and 5______ your arms out to the keyboard.
★Bring your 6______ up close to the keyboard so that you can rest your arms on the chair 7______ desk.
Keep your shoulders 8______.
★You need to rest and move around 9______ 30 minutes to let your body relax.
★Try bending (弯) back a few 10______ to help your body relax.