There are many changes that materials undergo which may be useful to the environment. Which of the following changes are not useful to the environment? 

Recycling and reusing materials are helpful to us and our environment. which of the following changes in the materials is useful for the environment?

Identify whether the following actions or changes of the materials are useful or harmful.

Deforestation, smog in cities, and a pile of garbage anywhere are examples of harmful changes to the environment.

Match each picture to its correct description.