trick

What's the trick to getting this chair to fold up?

把这张椅子折叠起来有什么诀窍？

She played a really nasty trick on me - she put syrup in my shampoo bottle!

她对我搞了一个很讨厌的恶作剧——把糖浆放进了我装洗发剂的瓶子里。