Directions: The following is a list of terms related to Security. After reading it, you
A ----------------- air traffic control system
B ----------------- armed police
C ----------------- crime prevention
D ----------------- entry requirement
E ----------------- international criminal police organization
F ----------------- level of security
G ----------------- picket line
H ----------------- police station
I ----------------- patrolling vehicle
J ----------------- safety precaution measure
K ----------------- safety control device
L ----------------- security command center
M ----------------- security service
N ----------------- security control center
O ----------------- security personnel
P ----------------- valid documents
Q ----------------- security monitoring and control
Examples: (M ) 保安服务 (G ) 警戒线
51. () 空中交通管制系统 () 安全预防措施
52. () 巡逻车 () 武装警察
53. () 国际刑警组织 () 有效证件
54. () 入境要求 () 安保人员
55. () 安全保障级别 () 安全监控