Years ago people could hardly accept the ideas of a woman's being a doctor.In order to get into medical school in 1847,Elizabeth Blackwell was asked to keep it a secret that she was a woman.This was _ to her beliefs,and she refused to do it.After entering medical school,Elizabeth often had to summon  all her courage to free the unkindness of teachers and classmates.By her great efforts,she was able to complete her studies.Many people came to her graduation just to have a look at a woman doctor.Doctor Blackwell soon found that most people were not as ready as to go to a woman doctor.She had to struggle to make a living.Then came the great day when she was offered a job as a doctor in a hospital.She did so well that she was asked to organize a new hospital and medical college.The United States can now be proud of thousands of women doctors. When she was at the medical school,Blackwell   _  .
had to pretend to be a boy student in class was discouraged by the others' critical looks felt sorry that she was a woman made great efforts to do well in her lessons