缩写的“Dr”或“Dr.”，是对获得博士学位的人的称呼。It is until the early 19th century the physician started using the doctor title， regardless whether they hold the doctorate or not . This matter has already been brought to WHO， that decides the title doctor granted to them as honorary calling because of their job contribution.
500 outside [ˈautˈsaid] prep./ n./ ad./ a.(在，向)的外面(的)501 piece [pi:s] n.片，块，段，件；断片，碎块 vt.拼合(凑)502 sometimes [ˈsʌmtaimz] ad.
Unit1 How can we become good leaders? textbook /tekstbuk/ n. 教科书；课本 p.1conversation /kɔnvəseɪʃn/, n. 交谈；谈话 aloud /əlaud/ adv. 大声地；出声地 p.
