单项选择题The discrepancies between these different analyses ______ a number of problems.
单项选择题The author's primary concern is to ______.
单项选择题The author regards the practice of using drugs for medically valid purposes before FDA approval as ______.
单项选择题All of the following are mentioned in the passage as reasons for allowing unlabeled uses of drugs except ______.
单项选择题The government should distinguish between unlabeled use and disapproved use of a drug by ______.