Overview. If you frequently experience shortness of breath or you hear a whistling or wheezy sound in your chest when you breathe, you may have asthma â a chronic condition that causes inflammation and narrowing of the bronchial tubes, the passageways that allow air to enter and leave the lungs.
1 At 47,958 kilometres (29,800 miles) in total length, the Pan-American Highway is the longest road in the world.  The road starts in Alaska, North America and ends in the lower reaches of South America.
10 Longest Interstate Highways (PHOTOS) On June 29, 1956, President Dwight Eisenhower signed the Federal-Aid Highway Act of 1956, which created a 41,000-mile National System of Interstate and Defense Highways that would become America's most important transportation infrastructureâand one of the world's modern wonders.