<prompt> Translate the following text to EnglishUpepo wa Sacre-Caur unatokana na mawe ya chokaa ya Chateau-Landon, ambayo hupungua wakati inapowasiliana na kaboni dioksidi katika hewa na kuwa ngumu kadiri inavyozeeka.  <response>: The Sacre-Caurs conspicuous whiteness comes from the local Chateau-Landon limestone, which bleaches on contact with carbon dioxide in the air and hardens with age. 