Page 9 If all the water in the atmosphere rained down at once, it would only cover the ground with a depth of 2.5 cm. Find out more about each part of the water cycle. Summary of the Water Cycle http://water.usgs.gov/edu/watercyclesummary.html This set of web pages from the U.S. Geological Survey is filled to the brim with information.
Page 174 You may have seen a one-way mirror (sometimes called a two-way mirror). If you stand on the brightly lit side of the mirror you see your own reflection. If you stand on the darker side of the mirror you can see through it, like a transparent window. Find out how it is possible to see through one way but not both ways.
Page 231 An optical or visual illusion tricks the eye and brain into perceiving something unlike what actually exists. Check out examples of optical illusions and find out what they reveal about the way we see. These Optical Illusions Trick Your Brain With Science http://www.wired.com/2014/11/optical-illusion-science/ Some great optical illusions can be observed here.