Mr Black, who we all admire, is a kind but strict teacher．
A. the one
B. it
C. one
D. as
网友回答
A. the one
B. it
(答案→)C. one
D. as
解析：考查代词：one代替的是专有名词Mr Black，故不用加the， one是定语从句的先行词。one who we all admire又含有定语从句的短语，one who we all admire是前面布莱克先生的同位语，句意：我们都很敬佩的布莱克先生是很好但很严格的老师。选C。