tack something on
phrasal verb with tack verb uk/tæk/ us/tæk/
informal
（临时）增补，附加
to add something that you had not planned to add, often without much preparation or thought
At the last minute they tacked on a couple of extra visits to my schedule. 在最后一刻，他们在我的日程安排上增加了几项额外的参观活动。