16. Transmission of the pneumonic plague from man to man is through

A. inoculation
B. ingestion
C. droplet infection
D. all of these

17. Which of the following genus belongs to family Spirochaetaceae?

A. Treponema
B. Spirochaeta
C. Borrelia
D. All of these

18. Which of the following bacteria is/are known as coliform bacilli?

A. Escherichia
B. Klebsiella
C. Enterobacter
D. All of these

19. The agent(s) which can cause plague is/are

A. Yersinia pestis
B. Proteus mirabilis
C. Pseudomonas aeruginosa
D. All of these

20. Salmonellae can also be killed by

A. pasteurization
B. chlorination
C. boiling
D. all of these