rate

/reɪt/

a magnitude or frequency relative to a time unit

中文释义：比率；速度；费率

The birth rate in the country has declined significantly over the past decade.

该国的出生率在过去十年中显著下降。

He drove at a steady rate of 60 miles per hour on the highway.

他在高速公路上以每小时60英里的稳定速度行驶。