21. More promising chemotherapeutic agents for treating viral diseases is

A. leukocytic interferon
B. fibroblast interferon
C. interferon
D. nystatin

22. A parenteral route of drug administration refers to

A. oral
B. nonoral
C. intravenously
D. intramuscularly

23. Which of the following antibiotics can’t be used for the treatment of infections with β-lactamase-producing Staphylococcus aureus?

A. Vancomycin
B. Ampicillin/sulbactam
C. Cephalothin
D. Piperacillin

24. Which of the following is not an aminoglycoside antibiotic?

A. Streptomycin
B. Neomycin
C. Kanamycin
D. Cephalosporin

25. The nitrofurans differ from the antibiotics in that they

A. does not occur naturally
B. occur naturally
C. are antimicrobial drugs
D. all of these