VOA慢速英语:美军训练在极端寒冷的环境下的作战

focus - n. to direct attention or effort at something specific

expose - v. to cause (someone) to experience something or to be influenced or affected by something

replicate - v. to repeat or copy (something) exactly

peer - n. a person who belongs to the same age group or social group as someone else

folks - n. people in general (informal)

casualty - n. a person who is hurt or killed during an accident, war, etc.

respond - v. to do something as a reaction to something that has happened or been done