Medical journals are publications that report medical information to physicians and other health professionals.
In the past，these journals were available only in print.With the development of electronic publishing，many medical journals now have Web sites on the Internet，and some journals publish only online.A few medical journals，like the Journal of the American Medical Association，are considered general medical journals because they cover many fields of medicine.Most medical journals are specialty journals that focus on a particular area of medicine.
Medical journals publish many types of articles.Research articles report the results of research studies on a range of topics varying from the basic mechanisms of diseases to clinical trials that compare outcomes of different treatments.Review articles summarize and analyze the information available on a specific topic based on a careful search of the medical literature.
Because the results of individual research studies can be affected by many factors，combining results from different studies on the same topic can be helpful in reaching conclusions about the scientific evidence for preventing，diagnosing or treating a particular disease.Case conferences and case reports may be published in medical journals to educate physicians about particular illnesses and how to treat at them.Editorials in medical journals are short essays that express the views of the authors，often regarding a research or review article published in the same issue.
Editorials provide perspective on how the current article fits with other information on the same topic.Letters to the editor provide a way for readers of the medical journal to express comments， questions or criticisms about articles published in that journal.
1. The main readers of medical journals are？
A）the general public.
2. Which of the following statements is NOT true？
A）Many medical journals also publish online.
B）A few medical journals are general medical journals.
C）Most medical journals publish only online.
D）Most medical journals are specialty journals.
3. How many major types of articles are mentioned in the passage？
4. An article dealing with results from different studies on the same topic is called？
A）a research article.
B）a review article.
C）a case report.
5.Letters to the editor enable readers of a medical journal to express comments on？
A）any medical event.
B）articles published in the same issue.
C）articles published in that journal