speed limit的复数形式怎么拼写？

A speed limit of 30 mph was introduced in built-up areas.在建筑密集区域，车速限制为每小时30英里。The speed limit on the freeway is 55mph.高速公路限速每小时55英里。to reduce the speed limit in built-up areas在楼房林立的地区降低最高车速限制...

speed limit的音标：speed limit的英式发音音标为：[spi:d 'limit]speed limit的美式发音音标为：[spid 'lɪmɪt]...

n.速度限制...