原因是的用法和樣例：
例句
-
地震本身的真正原因是地球表面的或地底下的岩石斷裂或破裂。
The actual cause of the quake itself is the rupturing or breaking of rocks at or below the earth's surface. -
這個地區疾病的主要原因是水不清潔。
A major cause of the disease in this area is unclean water. -
引發事故的間接原因是火車晚點。
The accident was the indirect result of the train being late. -
你缺席的真正原因是什麼？
What was the real reason for your absence?
