But in the absence of modern metal tools the Neolithic drill of choice 9,000 years ago was a flint head, according to Roberto Macchiarelli, of the University of Poitiers in France.
But in the absence of modern metal tools the Neolithic drill of choice 9,000 years ago was a flint head, according to Roberto Macchiarelli, of the University of Poitiers in France.
科学家日前公布的一项研究结果显示，早在电钻和麻醉剂发明之前，早期人类就开始通过在牙齿上钻孔的方法来医治蛀牙。