13. For many cities in the world, there is no room to spread out further, New York is an example.
14.
A. for which
B. in which
C. of which
D. from which
网友回答
A. for which
B. in which
(答案→)C. of which
D. from which
解析：解析：考查非限制性定语从句，从句还原后成为 “New York is an example of many cities”，所以选择介词of。