There have been about ten thousand antibiotics since Fleming discoveried penicillin in 1928, only one hundred kinds of antibacterial drugs have been introduced for clinical use.

• 自从1928年Fleming发现青霉素以来，人们已经发现了大约一万种抗生素，但真正具有临床价值的却不多，其中只有100多种投入了工业生产。