阅读下面短文, 在空白处填入1个适当的单词或括号内单词的正确形式。
How do people climb the wall? (climb), you need special shoes and a harness(保护带) your chest to hold you.There are ropes tied to your harness.The ropes hold you in place so that you don't fall.A
(begin) wall is usually about 15 feet high, and you climb straight up.
There are small pieces of metal that stick out for you to stand
and hold on to.Sometimes it's easy to see the new piece of metal.Sometimes, it's not.The most difficult part is to control fear.It's normal for humans to be afraid of falling, it's difficult not to feel fear.But when you move away from the wall, the harness and the ropes will hold you, and you will feel safe.You (move) slowly until you reach the top.
Climbing attracts people it's good exercise for almost everyone.You use your whole body, especially your arms and legs.This sport gives your body a complete workout.When you climb, your mind and your body can become (strong).