(And 20% don't know that hamburgers are made from beef. This grasp of knowledge explains the support for socialism, global warmism, free tuition, and a $1,000 minimum wage among Bernie Sander's young followers. Their elders have no excuse..)
UPDATE: apparently this report has gained national attention, but at least one commentator has taken it in stride: there are worse things to worry about.
Sadly, there are numerous far worse examples of public ignorance out there, including many about far more consequential issues. The 7 percent figure pales in comparison with the 25 percent who don’t know the earth orbits the sun, the 66 percent who can’t name the three branches of government, and – my personal favorite – the 80 percent who support mandatory labeling of food containing DNA.