1）使用《牛津英语搭配词典》查“viable”，了解它作为形容词时的常用搭配。
commercially/economically/financially/politically viable
prove/seem viable
2）翻译下面的句子：
中国经济下行，许多 O2O 模式显得不再可行。
As China's economy is going downhill, many O2O business models no longer seem economically viable.
参考翻译：As China’s economy is going downhill, many online-to-offline (O2O) businesses no longer seem (commercially/economically) viable.
