Understand how historians are like detectives- studying evidence from the past.

In this proofreading exercise, students read a sentence and decide if it is correct. If it is correct, they leave "Correct" in the box; if not, they use the drop-down menu and select the type of error they detected. Then they click check...

These interactive pictures focus on the vocabulary for common jobs. Pop-ups of the correct spelling appear, along with the audio of the correct Spanish pronunciation when the mouse is moved over each illustration.

We rely on the sun to sustain life, but there are many things about the sun that the human eye is unable to detect. This media rich site offers a spectacular look at coronal mass ejections, magnetic loops, and solar flares. Interactive...