- 疑难
- difficult
- 疑难
- knotty
- 疑难
- tough
- 疑难杂症
- difficult and complicated cases
- 疑难杂症
- tough and thorny questions
- 银弹
- silver bullet
- 银弹外交
- “silver bullet” [or dollar] diplomacy
- 阴暗
- dim
- 阴暗
- dark
- 阴暗
- gloomy
- 阴暗
- murky
- 阴暗的角落
- dark corner