关于引起锅炉事故的原因，分析不当的是( )。

A．省煤器损坏会造成锅炉缺水而被迫停炉

B．煤灰渣熔点低、燃烧设计不当易产生锅炉结渣

C．锅炉发生水击事件时，管道常因受压骤升而被破坏

D．尾部烟道二次燃烧主要发生在燃气锅炉上

There was a murder in one of the poorest suburbs in the city the other day. Now the police are turning the whole house upside down __________ clues.

A．in want of

B．in search of

C．in favor of

D．in need of