尽管我经常去纽约，但洛杉矶仍然是我的基地。

Although I travel frequently to New York, Los Angeles remains my ___base.

西雅图是探索太平洋西北地区的完美基地。

Seattle serves as a perfect ___base for exploring the Pacific Northwest.

这个沿海城镇是航运业的关键基地。

The coastal town functions as a key ___base for the shipping industry.