短文改错（共10小题，满分5分）

In order to go diving, you need some equipments. First divers carry their backs a metal bottle, which is filled of water. There’s enough air in it to last about 40 minutes. Next, divers carry heavy metal weights in a belt around its bodies.  With these heavy weights they would float to the surface.  You see, there are a lot of air in their air bottles, and this will bring them up to the   surface if they didn’t have any more weights.  Mostly divers don’t go very deep.

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