... nitrogen oxide which combine with the moisture in the atmosphere to form sulphuric acid and nitric acid 38. “This” means to pump limestone into the acidic lakes 39. They contains carbon monoxide and ... However, It is not possible to do this on a large enough scale to save all the lakes. Car exhaust fumes contain carbon monoxide and lead which are highly poisonous. In big cities, the exhaust ... yourself?” Caâu 7: (20 ñieåm) Dear Mike, 51. Last month, I went on an excursion to Paris 52. I went with some of my classmates 53. I got up early and met them at the station 54. In the morning,...