fill in the blank

(What) is Winnie's mother ?
She is a nurse.

(Who) is Winnie's mother ?
She is the nurse who takes care of your grand mother.

The answer to a "what" question about a person describes a categorization that the person belongs to. Therefore, "a" nurse can be used to describe the occupation of Winnie's mother, but it can not identiry who Winnie's mother is.

The answer to a "who" question about a person describes the identity of that particular person, so "a" nurse can not be used, instead, "the" nurse (who looks after your grand mother) specifically identities who shs is.

Filling in the blanks:-
Who=pron.=used in questions to ask about name,identity or function of people,eg:-Who is that woman?=A. Who is Winnie's mother? She is a nurse
The answer is A. Who.

B. Whose=pron.=used in question to ask who something belongs to=eg:-Whose house is that ?

C.What=pron. det.=used in questions to ask for particular information about somebody or something,eg:-What is your name? What job does she do=a nurse.

D. Where=adverb.,conjunction;
---adv.=in or to what place or situation:-eg:-Where do you live? Where will she take us to ? Where did I go wrong in my answer ?

呢 d 問題，只要打開字典查下四個答案的意思就識答啦，唔好咁懶！

這條....
答案是A, who is Winnie's mother? She is a nurse.