work up something
phrasal verb with work verb uk/wɜːk/ us/wɝːk/
激发，激起
to develop an emotional or physical state that you feel strongly, after a period of effort or time
We worked up a real appetite climbing in the mountains. 我们突然很想爬山。
It's strange, but I can't work up any enthusiasm for going on this trip. 很奇怪，这次旅行激不起我的任何热情。