例:lf you divide 26 by 2,the quotient is 13.
例:Raccoons are shy and active only at night.
词根记忆:rac(e)(种族)+ism(…主义)--种族主义
同根词:racist(n.种族主义者)
词根记忆:radi(光线,射线)+ant--发光的--容光焕发的
例:a radiant smile灿烂的笑容
同根词:radiation(n.发光,传播);radiator(n.散热器)
词根记忆:radi(光线)+ate--发光,放热--放射,辐射
例:The national observatory has been observing x-rays radiated by compact stars for years.
派生词:radiation(n.放射;放射物;放射线)
词根记忆:radic(根)+aI--根本不讲道理的--激进的
例:a radical feminist激进的女权主义者
派生词:radically( ad.彻底地;激进地)
词根记忆:radi(辑射:光线)+o+active(活跃的)--发射光活跃的--放射性的
例:Calcium carbonate shells contain radioactive material.
联想记忆:radio(无线的)+carbon(碳)--不经过实体传播的碳--放射性碳
例:Using new radiocarbon dating techniques, it was determined that the charcoal from the Colorado site was at least 11,400 years old.
注意:diameter(n.直径);circumference(n.圆周)
例:The radius of the circle is 0.5 meter.