All efforts to ______ him with his elder brother proved in vain; they didn't talk to each other as before.

单项选择题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 ______.