Seeing this, Brahma, the chief god, decided to take their divinity away from them and hide it 22 it could never be found.
答案：(C) where
關係副詞 where 引導地方子句，「藏在一個永遠找不到的地方」；though（雖然）、because（因為）、when（何時，這裡需要地方不是時間）都不合。
空格後面的 it could never be found 是一個完整的句子，看到完整句子你會反射性想填連接詞，於是在 because 與 though 之間猶豫。也有人看到 could never be found 想成時間先後，選了 when。
先看空格前面：hide it ______。「把它藏起來」之後，最需要交代的是「藏在哪裡」，也就是地點。where 可以直接引導一個表示地點的子句接在動詞後面，前面不必先出現 the place：hide it where it could never be found ＝ hide it in a place where it could never be found（把它藏在一個永遠找不到的地方）。這種用法你國中就見過最短的版本：Stay where you are.（待在原地）、Put it back where you found it.（放回你找到它的地方）。文法書對它有兩種處理方式，指的是同一件事：一種說 where 是連接詞，引導表示地點的副詞子句（劍橋 English Grammar Today 的 where as a conjunction）；另一種說它是關係副詞，先行詞 the place 被省略了。不論採用哪一種說法，判斷的關鍵都一樣——句子缺的是地點。
though：雖然，讓步語意，「雖然它永遠找不到」與「把它藏起來」接不上。because：因為，因果方向顛倒；不是「因為找不到所以藏」，而是「藏起來讓人找不到」。when：引導時間子句，但句子缺的是地點不是時間，hide it when it could never be found（在它永遠找不到的時候藏它）根本講不通。
hide something from somebody（把某物藏起來不讓某人發現）、take something away from somebody（從某人身上奪走某物）、decide on（決定、選定）、call a council（召開會議）、be found（被找到）、the chief god（眾神之首）。
There was once a time when all human beings were gods. However, they often took their divinity for granted and 21 abused it. Seeing this, Brahma, the chief god, decided to take their divinity away from them and hide it 22 it could never be found.
Brahma called a council of the gods to help him decide on a place to hide the divinity. The gods suggested that they hide it 23 in the earth or take it to the top of the highest mountain. But Brahma thought 24 would do because he believed humans would dig into the earth and climb every mountain, and eventually find it. So, the gods gave up.
Brahma thought for a long time and finally decided to hide their divinity in the center of their own being, for humans would never think to 25 it there. Since that time humans have been going up and down the earth, digging, climbing, and exploring—searching for something already within themselves.