Geometric mean radius

geometric [dʒiə'metrik]

adj. 几何学的;成几何级数增减的;几何装饰的;

mean [min]

v. 表示…的意思;意思是;打算;产生…结果; adj. 吝啬的;刻薄的;破旧的;残忍的; n. 平均数;中间;几何平均;等比中数;

radius ['redɪəs]

n. 半径（距离）;用半径度量的圆形面积;半径范围;桡骨;

radi光线 + us 用→ 用光线扫出一个圆，则光线是→半径

Sorry, but he is out at the moment.

抱歉，他现在出去了？

Wouldn't that be too much bother?

不会太麻烦吧？

The only way that they can preserve their history is to recount it as sagas -- legends handed down from one generation of another.These legends are useful because they can tell us something about migrations of people who lived long ago, but none could wri

他们保存历史的唯一办法是将历史当作传说讲述，由讲述人一代接一代地将史实描述为传奇故事口传下来。