快慢的英文：
speed

参考例句：

Regulator head (for two-piece regulator)
快慢针头(对开快慢针用)

The government lost the argument over the pace of reform.
政府在有关改革步调快慢的争论中是输家。

Cancers are described as more or less malignant in proportion as they are more or less rapidly growing and invasive
癌生长的快慢和侵袭性的大小与它的恶性程度成正比。

If accretion takes place in eccentric orbits as well, the rotation will be prograde and of the right order of magnitude
如果吸积发生在偏心轨道，则自转将是正向的，且快慢也合适。

speed是什么意思：
n. 速度，速率；快速，迅速
v. 迅速前进，快行；促进；加速，使加速

The speed of a train differs greatly from the speed of an airplane
火车的速度与飞机的速度大不相同。

The car is gaining speed.
那辆轿车正在加速。

The worker is timing the speed of the machine.
这名工人正在调整机器的速度。

a dizzy height, speed
使人眩晕的高度、 速度.

Speed the parting guest
祝客人一路顺风