Question

describe two changes that are harmful why considered harmful how can you prevent them

Answer 1

not able to get the question

Answer 2

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1.Rusting Of Iron:

If a bicycle's chain get's rusted,it may result in breakage of bicycle chain.

Prevention:

Apply grease on it regularly.

2.Burning Of wood:

When wood is burnt, it releases harmful gas and pollutes the earth.

Prevention:

Use clean fuels like CNG,LPG,etc

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