### Chinese: 诞生12年，比特币在2021年迎来了几个里程碑事件。
### English: Twelve years after its birth, Bitcoin met several <v>milestones</v> events in 2021.
### Errors: There is a minor fluency/grammar error at "milestones" within <v></v>.

### Improved English: After coming into being 12 years ago, bitcoins ushered in several milestone events in 2021.
