科學(xué)60秒:啤酒作藥 美哉樂哉

文章較難，大家聽寫填空即可~
In 1980, a scientist looking at bone fragments under an ultraviolet microscope noticed the bones were glowing green -- a hallmark of the antibiotic tetracycline. The drug ____1____ calcium and ____2____ bone. Nothing unusual. Except these bones were from a Nubian mummy buried 1,600 years ago in Sudan -- long before scientists discovered tetracycline, in 1948.
At the time, other scientists said the antibiotic probably just contaminated the bones after death. Because tetracycline’s secreted by a soil bacterium, Streptomyces. To ____3____ this, a chemist recently took bone from the mummy of a Nubian child and dissolved it in hydrogen fluoride, a ____4____ that helps extract tetracycline. And this bone extract also matched the chemical signature of tetracycline -- evidence that the antibiotic was built into the kid's bones as he grew. That analysis appears in the American Journal of Physical Anthropology.
Anthropologists know the Nubians were skilled brewers. Researchers now believe that the ancient brewmasters learned to purposely make their beer medicinal, by ____5____ grain contaminated with antibiotic-producing Streptomyces bacteria. Just imagine that prescription.