According to the passage, an unlabeled use of a drug is any use that ______.

单项选择题A patient who is dying of incurable cancer of the throat is in terrible pain, which can no longer be satisfactorily ______.

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 ______.