1. The balloon suddenly popped the scared the hell out of me.2. A kid kept waving his balloon at me until I got annoyed and popped it with my pencil. Then he cried his eyes out.
 pop (a balloon, etc.) expose (a secret, etc.)pop 用在戳破氣球等的東西, expose 用在戳破祕密或謊言等
I have been wecking my brain on this tough math question but I still cannot solve it.