RALEIGH, N.C. -- North Carolina students had a little trouble with their reading skills, with scores on achievement tests dropping slightly in a national measure of student performance released Wednesday. Nearly 40 percent of fourth-graders and 31 percent of eighth-graders performed below a basic level of proficiency in reading, according to the National Assessment of Educational Progress, or NAEP. But math scores held steady for both grade groups, and the North Carolina students generally performed at or slightly better than the national average in both subjects. "The trendline for North Carolina students is positive in mathematics. This year we held...