Volley and obstruct are good technique in ping - pong sport 拦击和阻挡在乒乓球比赛中是很好的技术。
2.
With the development of aerospace science , especially the appearance of high speed attack weapons such as guided missile , radar is required to not only discover and track the target in further distance but also command plane and missile to head off the target 随着空间技术的发展,特别是导弹等高速进攻性武器的出现,要求雷达能在更远的距离上发现和跟踪目标,并能及时指挥和引导飞机和导弹拦击目标。
