idiom
a double-edged sword
既有正面又有负面后果的事物
Meaning
something that has both positive and negative consequences
Example
The internet is **a double-edged sword**; it provides vast information but also exposes us to privacy risks.
互联网是**a double-edged sword**; 它提供了大量的信息,但也使我们面临隐私风险。