Those tests are a bit unfair, though I do not deny that the typical american school is behind many others. In places like china and many other eur-asian countries, children get weeded out since elementary school. The intelligent ones go on, the less intelligent go on to learn a trade. In middle school, the very intelligent go on to better schools, the rest go on to learn more skilled trades. so that, even at 15, the kids in schools are generally only the very smart ones.
Also, america has that little "no child left behind" policy, which not only stunts the speed and depth of material covered in classes, but also ensures that even kids with no potential or drive for education HAVE to go to school.
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...life is good...
...mai ho oni i ka wai lana malie...