1. It is true that important achievements in medicine have been made recently.
2. The scientist had been studying the effects of the drug on laboratory animals for a month already when he found this article.
3. Vaccination being used in time, the disease did not affect many people in this area.
4. Having examined the patient the doctor prescribed him bed rest and a course of injections.
5. The student has been working over this problem for two weeks already.
6. Lungs are said to have been involved in the process.
7. The virus has been growing in culture medium for 2 days already.
8. Since you had to do the examination of the area two days ago you are to give me the report just now.
9. The study of this infection has been slowly progressing for the last 10 days.
10. The drug was being produced in our department from September 12 to November 30 last year
11. The neurologist having examined this patient did not find any pathology.
12. The patient’s parents are talking with the doctor in charge now
13. We have been performing our research for four months already
14. The drug having been tested on animals was recommended for clinical use.
15. The patient had been sleeping for two hours when the nurse came to give him the injection.
16. The students had been writing the test-paper for 40 minutes already when I came.
17. By the end of this year he will have been working in the Research Center for Pulmonology for 15 years already.
18. Having examined the patient the doctor prescribed him bed rest and a course of injections.
19. The patient had been operated on by 12 o’clock yesterday.
20. The patient had been examined for the presence of staphylococci in his blood before the therapy was begun.