It's a clump of foreign matter that couldn't be expelled with a prokinetic agent.

他是不能被胃动力促进剂所排泄的一团异物。

In addition, foreign matter in the breathing passages can often be ejected by nose blowing, coughing, sneezing, and throat clearing.

不幸的是反复感染、抽烟或其它原因会损坏呼吸道，并且使它们更容易受到感染。