Nationally-known testing experts are joining state education officials in defending Minnesota's 8th grade reading exam. The basic skills test came under fire last week, when the Association of Metropolitan School Districts claimed it's harder than an 8th grade reading level. Representatives of the association and state leaders squared off yesterday during a House subcommittee hearing on the test debate. Minnesota Public Radio's Tim Pugmire reports... Thousands of Minnesota students have failed the 8th grade basic skills tests each of the past three years. But the scores are rising. Results from this year's tests, released last week, showed a nine percent jump in reading, while math scores improved just one-percent for a year ago