This can be a problem even though earwax appears to serve an important purpose.

VOA: special.2010.03.31

Sometimes they serve a purpose.

有些能达到阐述的目的

耶鲁公开课 - 基础物理课程节选

In a White House statement, President Obama said the bombings "serve no purpose other than the murder of innocent men, women and children."

VOA: standard.2009.10.26