Field Trip

Jessica took her students on a field trip around Cairo looking for evidence 0of pollution. Needless to say, it wasn't hard to find:

This is a photo of the Pyramids. They're across the valley, about 8 miles away. On a clear day, they're closs enough to see the outlines of the slabs of rock. That happens about ten times a year, at best. They're visible from across the valley (meaning you can at least see their outline through the smog) about 10% of the time.