Definition: someone who gives information to the police, newspapers, etc. Level: C1
记者从一位保密的消息人士那里获得了信息。
The journalist received the information from a confidential ___source.
调查人员正试图保护他们的主要线人。
Investigators are trying to protect their main ___source.
根据警方的消息来源，嫌疑人已经离开了这个国家。
According to police ___sources, the suspect has left the country.
