Then oil prices soared, resulting in a seven-fold increase in income per head in Yemen, where elaborately carved rhino-horn dagger handles are prized as a sign of status and wealth.
Adding folic acid to diets costs four or five cents per head per year, with a payback of perhaps 120-fold.
而在食物中添加叶酸仅需每人每年四到五美分，其收益可能达120倍之多。
3
Conclusion Part of annular ligament or synovial fold interposed between the capitellum and the radial head could explain the mechanism of the pulled elbow.