one/ones 物主代詞
例題：He is a strict but kind-hearted father D the children respect but are afraid of.
A 不填 B that C for whom D one whom
這道題涉及到一個知識點，就是物主代詞的用法。這裏之所以選擇D，是因爲one代替句中的a father。做題的時候，這句話的前半部分可以省略爲最簡單的一句話是 He is a father，後面接的是以father爲先行詞的定語從句。但是從句部分沒有先行詞，就需要一個詞來充當先行詞，因爲是 a/an +單數名詞，即a father,所以用 one來代替。因爲從句中 but are afraid of後面缺少成分（賓語），所以要用whom來作連接詞。所以答案選擇D。
還有一些與此類似的代詞，以後遇見這樣的題就可以看是否需要一個詞來代替句中的單詞。
規律：a/an +單數名詞---------one
the +單數名詞---------that
複數名詞----------ones
the+複數名詞---------those
the+不可數名詞-------that
eg:Clothing made of man*made fibres(纖維) has certain advantages over__C____made of natural fibres like cotton,wool or silk.
A the ones B one C that D what
The students who do best in examination are not always___C___with the best brains.
A ones B that C those D the one