One should do such things oneself.
そうしたことは自分ですべきだ
One should never do injury to another person.
他人を不当に扱うべきではない
One small step for a man, one giant leap for mankind.
一人の人間には小さな一歩だが,人類にとっては大きな飛躍である(◆N. Armstrongの言葉)
One swallow does not make a summer.
((諺))ツバメ一羽が来ただけでは夏にならない;早合点は禁物だ
one third [two thirds] of the total
全体の3分の1[3分の2]
One Way
((掲示))一方通行
one way or (the) other
どちらかの方向に;どちらにしても
one way or another
なんとかして
one week shy of one's eleventh birthday
11歳の誕生日の一週間前に
one's (Sunday) best
((やや古))よそゆきの服
one's ability as a leader
指導者としての才
one's academic background
学歴
one's ancestral acres
先祖伝来の土地
one's appointed lot
宿命
one's arch [main] rival
一番の競争相手
one's aunt by marriage
妻[夫]のおば
one's behavior at meals
食事時の作法
one's beloved daughter
愛娘
one's better self
よい面,良心
one's biggest [largest, best] customer
上得意の客
one's bitter [old] rival
激しく張り合う[かつての]競争相手
one's bottom lip
下唇
one's bounden duty
義務,本分
one's bread and water
パンと水,粗食
one's capabilities as a musician
音楽家としての素質
one's capability for a job
仕事への適応性
one's childhood memories
子どものころの思い出
one's clarity of vision [purpose]
将来の見通し[目的]が明快であること
one's competence for a task
任務遂行能力
one's competitive edge
競争上のわずかな優位(点)
one's daily bread
日々の糧(◆聖書より);生計を立てる道
one's daily routine
日課
one's daring adventure
向こう見ずな冒険
one's debut [solo] album
デビュー[ソロ]アルバム
one's disgust for [of] obscene jokes
下品な冗談に対する嫌悪
one's dying hour
臨終のとき
one's dying wish
いまわの願い;遺言
one's dying words
辞世の言葉
one's elder brother [sister]
兄[姉]
one's elder son [daughter]
上の息子[娘]
one's elders and betters
目上の人々
one's eldest brother
一番上の兄
one's eldest son [daughter]
長男[長女]
one's entire life
一生
one's escape line
逃げ口上
one's everlasting puns
退屈なだじゃれ
one's exclusive hobby
唯一の趣味
one's express wish
自分のはっきりした希望
one's eyes heavy with sleep
眠そうな目
one's facial expression
顔の表情