The Federal Reserve Bank of Minneapolis provides teachers with a study guide showing students how to detect whether or not the currency that they are circulating is real or counterfeit. Back to Top Click on any of the vocabulary words below to hear them pronounced and used in a sentence. He was asked to determine the age of the controversial map. Among painters, titanium white is well known. A cyclotron creates a high speed beam of protons.
Caves provide a sanctuary for some of our earliest ancestors.
A subterranean river called the Logsbin. A weak, unstable acid present in solutions of carbon dioxide in water. Carbonic acid gently but persistently eats away the limestone. A quartz-like mineral called chert. Designating the era of geologic time between the Precambrian Era and the Mesozoic Era, characterized by the appearance of marine invertebrates, primitive fishes, land plants and primitive reptiles.