警察使用盾牌保护自己免受伤害。

Police officers use a ___shield to protect themselves from harm.

在历史战役中，战士依赖剑和盾牌进行防御。

In historical battles, warriors relied on a sword and a ___shield for defense.

防暴队在抗议期间举着大型塑料盾牌前进。

The riot squad advanced behind large plastic ___shields during the protest.