Which of the following sentences is acceptable?
1. Please tell me when they will take a trip to the north of Taiwan.
2. Please tell me when they will go on a trip in the north of Taiwan.
Both sentences are acceptable but they could have different meanings.
"… go on / take a trip to the north…" usually mean the same.
"… go on a trip in the north…" suggests more strongly that the trip might be through various parts of the north, rather than just to the north.
not a teacher