阅读下面短文，在空格处填入一个适当的词或使用括号中单词的正确形式填空。

     Marie Curie (居里) was a great woman scientist. She was the 1______ (young) child in the family.

Her mother died of illness when Marie was 11 years old. In 1883, Marie graduated from a middle school.

How she wanted to go to college! But her family was so poor 2______ she could not continue to go to

college. She had to work as a 3______  (teach) in a private family. In 1892, she saved enough money to

continue her study. So she left for Paris and entered Paris University. In her college days, she 4______  (live)

a simple life. Every evening she would study in the University library until it closed, then she would go back

5______  her room and work until late at night.

---_______ matters to do the job well

---what you are or where you come from? [ ]

A. Which is it that

B. What it is that

C. Which it is that

D. What is it that