Either can become loose or caked with dust, and make noise as they vibrate.
Gianpaolo ayaa ku ammaanay Ra’iisulwasaare Abdiweli horumarka baaxadda leh ee uu ka sameeyey soo celinta amniga, Xiriirka maamula da dalka iyo Dowladda, Dib-u-heshiisiinta, Dastuurka iyo Roadmap ka.