What makes it so hard for the face-recognition systems to work effectively？
A. The computers are not so advanced
B. The faceprints of the mugshots fed in the computers are never identical with those of real persons.
C. It is very hard for the operators to learn to control the system.
D. People seldom look straight at the camera.
Kimberly Rugh Talked about her son's birthday party_______.
A. with her friends
B. with her colleagues
C. in the classroom
D. in an E-mail massage sent to her students
目前城市社会空间结构的主要研究方法有()。
A. 社会区分析和景观分析
B. 社会区分析和因子生态分析方法
C. 景观分析法和相互作用法
D. 社会区分析和相互作用法
不属于城市体系研究的三大内容的是()。
A. 城市规模等级结构
B. 城市职能分工
C. 城市空间组织结构
D. 城市分类
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