bring to a head的用法和样例：
- The pimple came to a head before bursting.
- Her burst of anger brought matters to a head.
- To bring to a bad or worse condition; debase.
- Matters have come to a head in the peace talk.
- Bring to a boil; reduce to a simmer.
- It was bringing to a head ideas and emotions that had been obscurely stirring inside her for months.