dent+ ist→dentist n.牙科醫(yī)生
例句：
The dentist told the boy not to eat too many sweets.
牙醫(yī)告誡這男孩不要吃太多糖果。
11.-ster：
young+ ster→youngster n.年輕人
例句：
That youngster works with a will.
這小伙子干活有股傻勁兒。
gang+ ster→gangster n.歹徒
例句：
The police are hard on the track of the gangster.
警察正在追蹤那名匪徒。
