Surfactant: A fluid secreted by the cells of the alveoli (the tiny air sacs in the lungs) that serves to reduce the surface tension of pulmonary fluids; surfactant contributes to the elastic properties of pulmonary tissue, preventing the alveoli from collapsing.urfactant: A fluid secreted by the cells of the alveoli (the tiny air sacs in the lungs) that serves to reduce the surface tension of pulmonary fluids; surfactant contributes to the elastic properties of pulmonary tissue, preventing the alveoli from collapsing.
Guy Fawkes' Day is not a public holiday. Businesses, organizations and schools are open as usual. Public transport services run to their normal timetables. Some organizations, communities and municipalities may organize public bonfires or displays of fireworks on or around November 5.
Photograph: Grace Chu4th of July Fireworks: Macy's Fourth of July Fireworks. Let the American Eagles fly and the red, white and blue bikini tops shine! Itâs time for 4th of July Fireworks, NYC's epic celebration of all things America and one of the most exciting things to do in summer. Check out the pyrotechnic spectacular as it bursts over the city's skyline and some of its best sights and attractions.