So, if you put it all together, this could help explain why today's college graduates, as well as less educated Americans, know less about the world than their counterparts did 20 years ago.
所以，想到所有这些，就能理解为什么比起20年前的同辈们 现在的大学毕业生，还包括一些教育程度较低的美国人 反而对世界了解的更少