在一定条件下，并非所有细胞都能融合，当细胞融合后需进行融合子的筛选，有关融合子的筛选

Complete the following passage with the words or phrases in the box. Each word can only be used once (将下列单词词组填入空格。每空格填一词，每词只能填一次

A. clothes     B. left    C. though       D. difficult E. parent      F. reading  G. happy with   H. angry about    I. came true

My mother was a housewife. She thought that successful people spent a lot more time __1___than watching TV. So she asked my brother and me to read two books every week in our free time. She would check them with marks, __2___she couldn’t read the books at all.
When I went to school, I was an A-student, but not for long. I wanted cool __3___ and hung out with friends. I went from being an A-student to a C-student, but I didn’t care. One night, I complained about not having enough Italian T-shirts. Then my mother gave me all her money. She said I could get the money __4__ to buy shirts if I finished buying all things the family needed. I was very __5__that, but after I bought those things, there was no money left. I got to know how _6__ it was for my mother to do all this. I went back to my studies and become an A-student again. Finally, my dream __7__ and I become a doctor.
My story is really my mother’s story--a woman with little education greatly changed my life as a __8__. So, I believe there is no job more important than parenting.