one做先行詞時，關系代詞用who來引導
定語從句宜用who來引導：當先行詞是those, she ,he ,they, ones, anyone, someone, no one等指人的代詞時。
例句：
One minus one is zero.
一減一等于零。
No one likes to lose.
沒人愿意失敗。