1. 这是什么词？
词：onset
英英释义：the beginning of something, especially something bad
例句：Evidence shows that speaking a second language can help delay the onset of dementia.
2. 为什么选这个词？
“onset”是个名词，意思是“开始”，常常可以用来完美替换常见的“beginning”，是外刊中经常出现的表达。onset 表示“开始”时，后面常接有负向含义的名词，比如疾病、经济萧条、战争等。
比如战争开始后，犯罪率激增，就可以说成：
Since the onset of the war, the crime rate has skyrocketed.
有证据表明，会说一门外语有助于推迟老年性痴呆（dementia）。我们就可以用 onset 造句：
Evidence shows that speaking a second language can help delay the onset of dementia.
最近的《经济学人》中也出现了 onset：
The study adds substantial weight to the evidence linking cannabis to the onset of psychosis.（“the onset of psychosis”指“精神疾病的开端”，这句话是说研究表明吸食大麻很有可能导致患上精神疾病）
3. 怎样学会使用这个词？
1）翻译下面的句子：
经济危机爆发后，投资面貌发生了巨大变化。
The investment landscape has been changed tremendously since the onset of the finnacial crisis
（参考翻译：The investment landscape has been changed tremendously since the onset of the financial crisis.）
2）结合自己的生活、学习、工作、兴趣等，想象在什么语境下会用到这个表达。先简要描述这个场景，再造句。
例子： 娱乐
场景 ： The onset of the scandal engulfs South Korea’s music industry. YG Entertainment, his former label, has seen its valuation plunge since the onset of the scandal. Whatever else the investigation reveals , it has already shown that, in the K-pop business at least, not all publicity is good publicity.
