security
n. 保护措施，安全工作；保安部门；安检处；保障，保证；安全，安全感；抵押品，保证金；证券，债券
复数 securities
例句
He was upgraded to security guard.
他被提升为保安。
《柯林斯英汉双解大词典》
She hasn't been cleared by security.
她尚未获保安部门批准做机要工作。
《牛津词典》
They had penetrated airport security.
他们已打入机场保安组织。
