it marked the boundary between the old City of London and Westminster

* Hướng dẫn giải

This gate is, in actual fact, not called a gate at all; its name is Temple Bar, and it marked the boundary between the old City of London and Westminster.
boundary: ranh giới, biên giới
Các từ còn lại:
division: sự phân chia
part: phần
line: đường, tuyến