Many doctors believe this decline in hormone levels triggers the symptoms of PMS. Changes in brain chemicals or deficiencies in certain vitamins and minerals may also play a role. Too many salty foods, alcohol, or caffeine may make symptoms worse as well.
There have been countless flights made since the invention of the airplane by the Wright Brothers in 1903. It should come as no surprise that the first commercial flight in history occurred in the United States. In fact, it occurred on January 1, 1914, three years before the United States entered the first World War.
Junkers F.13 D-335 became the first aircraft of the company, when Aero took delivery of it on March 14, 1924. The first flight was between Helsinki and Tallinn, capital of Estonia, and it took place on March 20, 1924, one week later.