drill – n. an exercise done to practice military skills or procedures

psychology – n. the science or study of the mind and behavior

trigger – n. something that causes something else to happen

trauma – n. a very difficult or unpleasant experience that causes someone to have mental or emotional problems usually for a long time

scare – v. frighten, to cause (someone) to become afraid

intruder – n. a person who is not welcome or wanted in a place

in advance – n. before something happens