题目

“You are the kind of person who will become a great doctor someday.” My mother whispered these last words of ______ as I approached the front door to go to school. The subject of my future, bound to be in the ______ profession, seemed to always come up whenever I came into contact with her. I ______ the idea of becoming a doctor because of the amount of work, effort and time you had to invest. The idea of ______ in biology and attending graduate school just did not seem to ______ me. Stepping out of the house, I replied perfunctorily (敷衍地), “______.Mother”The day began like any o如图，DE∥CB，OE=6，EC=21，DE=10，则CB的长为A.25B.20C.35D.30