Joseph Lutoff, age 13, Of Samerville, Mass., for his question:

How long is the Great Wall of China?

The Great Wall is long enough to stretch all the way from Boston, Mass., to Omaha, Neb. It bobs and weaves up hills and down dales. In some places there are breaks and some places there are branches. Altogether, the wall is more than 1500 miles long.

The job of building the Great Wall of China took hundreds of years, and all of the work was done by hand. It was started more than 2000 years ago to keep out the invading Tartars, and, at that time, there was no building machinery. The Great Wall rates as the longest fortification in the world, and it stretches through Northern and Northwestern China.