Administration: Individual. The DAB-4 is a revision of one of the most popular individual achievement tests available. Its 8 subtests identify studentsâ strengths and weaknesses across important areas of school achievement. A supplemental manual shows how to probe student responses to obtain information about studentsâ thinking processes and problem-solving strategies.
In 1992, the first evidence of a planetary system other than our own was discovered, orbiting the pulsar PSR B1257+12. Three years later, 51 Pegasi b, the first extrasolar planet around a Sunlike star, was discovered.
American astronomer Clyde Tombaugh discovered Pluto in 1930. From 1930 until 2006, Pluto sat comfortably beyond Neptune as the ninth planet in our solar system. In 2006, however, changes were made. The truth is, nothing about Pluto changed, but the definition of a planet did.