Corrugated cardboard has two main components: the linerboard and the medium. Both are made of a special kind of heavy paper. Linerboard is the flat facing that adheres to the medium. The medium is the wavy fluted paper in between the liners. Single Wall is manufactured with the medium between two sheets of linerboard. Double Wall has three sheets of linerboard with two mediums in between.
A new Microsoft-commissioned survey shows European girls lose interest in STEM subjects around the age of 15. Microsoft admitted it doesn't have a comprehensive explanation for why 15-year-old girls lose interest in science and math.
For example, the mathematics score averages of 17-year-olds declined from 1973 to 1982, then increased to a level in 1996 similar to the 1973 level. Long term trends in reading achievement show minimal changes across the assessment years. In 1996, the average reading score for 9-year-olds was higher than it was in 1971. Thirteen-year-olds showed moderate gains in reading achievement; in 1996, their average reading score was higher than that in 1971.