crossing security

例句：

1. 1. The crossingsecurity was a major concern for the cityauthorities.
   交叉安全是城市当局的一个主要关切。
2. 2.The crossing security system is designed to preventaccidents on the busy road.
   交叉安全系统旨在防止繁忙道路上的事故。
3. 3. The crossing securitycheckpoints were manned by police officersand soldiers.
   交叉安全检查站由警察和士兵负责看守。