n.环;轮;体环;[数]圆环域
What touch with vaccinal annulus is adhesive. 用接种环触之有粘性。
The thin ring of sunshine encircling the moon during an annular eclipse is called an annulus. 在日环食期间,绕着月亮的那轮浅浅的太阳光就被称为环面。
n.环带物(环形套筒;圆;圈)