?诱导性毒品
一堆盎格鲁-萨克逊时期的硬币——英格兰早期的证据 对我来说，罗马硬币充当着诱导性毒品(gateway drug)的角色。埃塞尔斯坦是阿尔弗雷德大帝的孙子，当时我需要写一部关于埃塞尔斯坦的传记，这个过程让我收集硬币的癖好达到了巅峰。
先导药
Copies act as a kind of gateway drug to the harder (or, at least, more expensive) stuff.
WSJ: In Praise of the Copycats: The Knockoff Economy
Downing characterized the six second Vine videos as light and fun, a sort of gateway drug between image sharing and video sharing.
FORBES: Will Vine Destroy Tout? Hardly, Says Tout's CEO
And it could be a gateway drug leading teens to real-world narcotics.
FORBES: Are Your Kids Getting High On MP3s? Hopefully...
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。