a double-edged weapon的用法和样例：
- Abstract: Flourishing market economy is a ＂double edged sword＂.
摘 要: 繁荣的市场经济像一把“双刃剑”。
- Therefore the deficiency of pre-Cambrian fossil and the sudden emergence of Cambrian trilobite are like a double edged sword posing threat for the very foundation of Darwin evolutionism.
- I do not realize it is a double feature.
- I want a double room with a view.
- He was so fat that he had a double chin.