缘由用英语怎么说？

缘由

例句

• Even successful bosses need to be queried about the whys and wherefores of their actions. 即使是成功的老板也要对其行动的缘由加以质疑。
• I called McCarthy, one of the French garcons , and asked him the cause of the conflict. 我叫住一位法国侍者麦卡锡, 问他争执的缘由.