YOU SAID:
It is discovered that the other trainees come from a variety of backgrounds, most being voluntary recruits from both populations on the ground, and others from colonies in the tunnels. During this time the party also learns they are in a large complex underneath the ground.
INTO JAPANESE
それは、他の研修生は、さまざまな背景から来る、トンネル内のコロニーから、地面に両方の人口から募集ほとんど自発的であることを発見しました。この時間の間に党はまた彼らは地面の下に大規模な複合体、学習します。
You've done this before, haven't you.