GETTING MY خانه TO WORK

At transonic speeds (close to the speed of sound), it helps to sweep the wing backwards or forwards to lower drag from supersonic shock waves as they start to variety. The swept wing is simply a straight wing swept backwards or forwards.گوتارد اکسپرس، سوئیس، ۱۸۹۷ آغاز به کار قطارها به سدهٔ ۱۵۰۰ میل