sour: v. to express annoyance or disappointment about something you think is unsatisfactory or unfair
翻译
他和母亲的关系突然变得很僵。
His relationship with his mother soured suddenly.
造句
句子: The cut-throat business of instant noodles soured because of the rising service of takeaway.
翻译: 竞争激烈的方便面市场因为外卖服务的兴起而变得更加糟糕。
背景: 产业的降维打击。