Definition: how often something happens, or how many people something happens to Level: B2
这座城市的犯罪率今年大幅下降了。
The city's crime ___rate has significantly decreased this year.
这个国家拥有全球最低的出生率之一。
The country has one of the lowest birth ___rates in the world.
这种新疗法的成功率超过90%。
The success ___rate for this new medical treatment is over 90%.
