英语解释：They carried out security checks at the airport.
他们在机场实行了安全检查。
the activities involved in protecting a country, building or person against attack, danger, etc. 保护措施；安全工作:
英语解释：They carried out security checks at the airport.
他们在机场实行了安全检查。
the activities involved in protecting a country, building or person against attack, danger, etc. 保护措施；安全工作:
