created sense approved 开球/開球 · kāiqiú · kick off
开球 / 開球
kāiqiú
kick off
to start a ball game, such as by kicking off in soccer or teeing off in golf
裁判哨声一响，比赛正式开球。
verb
created sense approved 开球/開球 · kāiqiú · open ball
开球 / 開球
kāiqiú
open ball
an open set of points within a fixed distance from a center point in a metric space
在拓扑学中，开球是构成开集的基础。
verb