Question

complete the sentence with the correct plural.
secretary of defense
blank have a sworn duty to advise the president on all military
matters and to oversee the united states department of defense.
submit

Explanation:

To form the plural of "Secretary of defense", we follow the rule for compound titles. The main noun "Secretary" is made plural. The plural of "Secretary" is "Secretaries", so the correct plural form is "Secretaries of defense".

Answer:

Secretaries of defense