1ADV 顺便谈及;顺便提一下 You use incidentally to introduce a point which is not directly relevant to what you are saying, often a question or extra information that you have just thought of. 顺便谈及;顺便提一下
'I didn't ask you to come. Incidentally, why have you come?'
“我没有叫你来。顺便问一下,你为什么过来?”
The tower, incidentally, dates from the twelfth century.