英和和英

30 km per hour

100 miles per hour

at a speed of forty miles an hour

at the [a] rate of 40 miles an hour

at (the [a] rate of) 40 miles an hour

at the rate of 60 miles an hour

do a ton

at 15 meters a second

do a ton

at half speed

lessen the speed

Three thousand kilograms.

drive at a constant speed

the car gathers speed

The wind is blowing at (a speed [velocity] of) 20 meters per second.

at an average of 50 kilometers an hour

equal speed

speed up

travel at a speed of 30 miles an hour

at a regular speed

speeds above thirty miles an hour

forward speed

My car does 12 km to the liter.

at full speed

at full speed

a speed of 300 revolutions per minute

lessen the momentum or velocity of

at double the speed

a slow speed

at top speed