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.
The Longest Road in America. Route 66 might be known as America's Mother Road, but U.S. Route 20 is, without question, the Big Daddy. It's America's longest road, stretching from Boston, Massachusetts to Newport, Oregon. That's 12 states and 3,365 miles of transcontinental American awesomeness to explore.