There is one step the TSA could take that would not require remodeling airports or rushing to hire: Enroll more people in the PreCheck program.
【句子结构分析】
本句中有两个定语从句修饰限定one step,第一个定语从句省略了关系词, 冒号后面是one step的内容。
【重点词汇】
the TSA: the Transportation Security Administration美国运输安全管理局
step: n. one of a series of things that you do in order to achieve sth 步骤；措施
remodel: v. to change the structure or shape of sth 改变……的结构
enrol: v. to arrange for yourself or for sb else to officially join a course, school, etc. (使)加入；注册；登记
【句子参考译文】
美国运输安全管理局可以采取一个不需要改变机场结构或者匆忙招聘员工的措施：使更多的人加入预检程序。