[U]（从高处俯瞰时感到的）眩晕，头晕目眩
the feeling of dizziness and fear, and of losing your balance, that is caused in some people when they look down from a very high place
问题1，the feeling of dizziness and fear, and of losing your balance这个短语是不是省略了同位语？
还原为the feeling of dizziness and the feeling of fear, and the feeling of of losing your balance
问题2，that不能引导非限拟定语从句，尽管这里有逗号，但依旧表示为限制性定语从句，并且【先行项】为feeling of dizziness and fear, and of losing your balance
the feeling of dizziness and fear, and of losing your balance, that is caused in some people when they look down from a very high place
that 引导定语从句，修护the feeling。前面虽有逗号，但不是非限制性的。在 balance 之后的逗号，是由于and 前有逗号，为了对称而作的停顿。用that 或which 都没错。
the feeling of dizziness and fear, and of losing your balance, that is caused in some people when they look down from a very high place ——
整个是一个名词性词组。of dizziness and fear, and of losing your balance 是the feeling 的定语，that...place 是定语从句，when...place 是定语从句中的时间从句。
