出典:Wiktionary
zealous efforts
persistent efforts
persistent efforts
piffling efforts
piffling efforts
feeble efforts
desperate efforts
desperate efforts
努力する.
untiring efforts
untiring efforts
むだな努力
fruitless efforts
むだな努力
sustained efforts
efforts paid off
unrelenting efforts
productive efforts
「efforts」は名詞「effort」の複数形です