How do we use soft materials? What is the hardest material of all? Can thingschange from hard to soft? Read Soft and Hard to find out Learn how some thingscan b... » 

How do we use soft materials? What is the hardest material of all? Can thingschange from hard to soft? Read Soft and Hard to find out Learn how some thingscan be made from both soft and hard materials how air can make things softand how things can change from soft to hard. Each book in the My World ofScience series explains science that you see in the world around you and useevery day. «