chief cause

• 首要原因

chief cause的用法和样例：

例句

1. It is the leading cause of suicide.
   抑郁是自杀的首要原因。
2. Further, Dunbar notes that behavior issues are the number-one cause of relinquishment to shelters.
   此外，他还指出，行为问题是导致犬类离家出走的首要原因。