阅读下列短文，然后根据短文的内容从每小题的四个选择项中选出最佳的一项。

     It is not easy to become a doctor in the United States. The first step is getting into medical schools. More than 120 American schools offer study programs for people wanting to be doctors.
     Advice about medical schools can be got from books and magazines like The Princeton Review, which provide information about medical schools, study programs and jobs. Competition (竞争) to enter medical schools is strong. American medical schools have only about 16,000 openings for students each year. However, more than two times this many want to enter medical schools.
     An important part of their application (申请) is the Medical College Admission Test (MCAT). The Association of American Medical Colleges provides the test by computer. It is offered in the United States and in other countries. Applicants need to do well on MCAT. They also need a good record in their college studies.
     An interview (面试) is also required for entrance to medical schools. The interviewer wants to know if the applicant understands the demands of life as a medical student and doctor in training. He also wants to know about the applicant’s goals for a life in medicine.
     People who want to become doctors often study a lot of biology, chemistry or other science. Some students work for a year or two in a medical or research job before they attempt to enter medical schools.
     A medical education can cost a lot, from 15,000 dollars to 40,000 dollars a year or more. Most students need to borrow money to pay for the education.