警察/一般警察/鐵路（三四等、員級）◆英文題庫下載題庫

Twitter is a social network that allows users to send and 46 short messages, called tweets. Tweets can be 47 140 characters long. You can post an upcoming event, organize group conversations or just tell the world 48 you are at the moment. Twitter has become very 49 . Since its birth in 2006 ever one hundred million people around the world 50 it regularly.