The derailed cars were carrying hot asphalt and molten sulfur, officials said. Cleanup is continuing at the site where a train carrying potentially hazardous materials derailed into the Yellowstone ...

Good morning! Lovely day outside. Hmm. Windows are made of transparent materials like glass or clear plastic because if they were made of opaque materials such as wood, well it wouldn't work would it?

Solids, liquids and gases are called the three states of matter. Liquids can flow or be poured easily. They are not easy to hold. Liquids change their shape depending on the container they are in.