Task: Question Answering
Input (English): Passage: Agonist-antagonist -- In pharmacology the term agonist-antagonist or mixed agonist/antagonist is used to refer to a drug which under some conditions behaves as an agonist (a substance that fully activates the receptor that it binds to) while under other conditions, behaves as an antagonist (a substance that binds to a receptor but does not activate and can block the activity of other agonists).
Question: can a drug be an agonist and antagonist
Output (English): 1