yard - metre, acre - ?

HECTARE
List of words for the clue yard - metre, acre - ? from the crossword:
ROO METER FOOT STERE LITRE ROOD EEYORE POUND GALLON ROODS TIME PROSODY MEASURE M KILOLITRE KILOLITER KILOGRAM CENTARE CADENCE
WordClue
ACREmetre - yard, hectare - ?
INCHhectare - acre, centemetre - ?
MASSmeter - distance, kilogram - ?
MILEhectare - acre, kilometre - ?
TIMEmeter - distance, second - ?
YARDhectare - acre, metre - ?
LITREyard - metre, gallon - ?
METREacre - hectare, yard - ?
POUNDmetre - yard, kilogram - ?
GALLONmetre - yard, litre - ?
SECONDdistance - meter, time - ?
HUNDREDFranklin, yard
DISTANCEsecond - time, meter - ?
KILOGRAMyard - metre, pound - ?
KILOMETREacre - hectare, mile - ?
CENTEMETREacre - hectare, inch - ?
PULLyank, tug
LITREyard - metre, gallon - ?