a can of worms的用法和样例：
- While fishing, he usually opens a can of worms.
- Don't open a can of worms by discussing this touchy issue.
- Tom can't sit still for a minute-he is a can of worms.
- What he left behind after his resignation was just a can of worm.
- Mr. Chen has opened a can of worms because of his controversial belief.
- I really opened up a can of worms when I asked him how his marriage was.