The soldiers practiced under battle conditions. what is the noun used as an adjective and the noun it modifies

The noun used as an adjective is "battle" and the noun it modifies is "conditions"

what class or school are you in i may

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).