While taking a 20-hour train ride along the edge of the Taklimakan Desert in the northwestern China, I had the kind of humbling, educational, and above all else, wonderful ___41___ with a local that all travelers long for. A young Chinese man ___42___ me on the train. My ___43___ friend spoke virtually no English, so I happily took the ___44___ to practice my Chinese.

上面的内容摘自2024年1月浙江卷普通高等学校招生全国统一考试题(完形填空)，请问其中的northwestern China前要不要定冠词？我见到在其他书上是不用定冠词的。