这家公司通过抢先获得关键专利来保护自己的市场份额。

The company protected its market share by ___preemption of key patents.

政府保留了这片土地的优先购买权。

The government retains the ___preemption right to purchase this piece of land first.

新调度系统的优先级更高，导致了旧系统的抢占。

The new scheduling system caused ___preemption of the old one due to its higher priority.