The plane hit speeds of around 98 mph.这句话里speed为什么用复数

The plane hit speeds of around 98 mph.这句话里speed为什么用复数 reached speeds over 600miles an hour.speed为什么要加复数? the car is run a speed of 60mph on road. reach a speed of和reach speeds有什么区别? hit the plane at speed of 和at speeds of 有什么区别吗? In the most scared room of the temple这句话中的room为什么不用复数形式? the speed of The boy hit a home run 中的boy是第三人称单数,为什么hit不要变复数? a blast of water hit the house,flinging open the door.这句话中,o What is the price of these sweaters?这句话不是复数吗?为什么要用is?事先声明：这句 Many of the songs were major hits.这句话怎么翻译,major和hit分别是什么意思