Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
download - v. to move or copy a file or program from a computer system to another or device
app - n. a computer program that performs a special function (short for application)
transaction - n. the act or process of passing money or information... from one to another
prohibition - n. a law or order that stops something from being used or done
update - v. to change something by including the latest information or function
functional - adj. working properly
