kilometre - mile, kilogram - ?

POUND
List of words for the clue kilometre - mile, kilogram - ? from the crossword:
ACRE INCH LITRE HECTARE GALLON CENTEMETRE UNIT MARATHON YARD LITER KM KLICK KILOMETER TONNES MASS MI TIME SECOND METRE
WordClue
ACREkilometre - mile, hectare - ?
INCHkilometre - mile, centemetre - ?
MASSsecond - time, kilogram - ?
MILEkilogram - pound, kilometre - ?
TIMEkilogram - mass, second - ?
UNITinch or mile
YARDkilogram - pound, metre - ?
LITREmile - kilometre, gallon - ?
METERmass - kilogram, distance - ?
METREpound - kilogram, yard - ?
GALLONkilometre - mile, litre - ?
SECONDmass - kilogram, time - ?
HECTAREmile - kilometre, acre - ?
DISTANCEkilogram - mass, meter - ?
KILOGRAMmile - kilometre, pound - ?
MARATHON42.195 kilometre road race
KILOMETREpound - kilogram, mile - ?
CENTEMETREmile - kilometre, inch - ?
ACREkilometre - mile, hectare - ?
GALLONkilometre - mile, litre - ?