No one knows for certain what happened, but it's a fair bet that it was not an accident.
没有人知道究竟发生了什么,但几乎可以肯定这并非意外。
He was a shrewd and wealthy businessman, but most people in the town hardly knew anything about this side of his life.
他是个精明能干、有钱的商人,但镇上大部分人对他生活中的这一个方面几乎一无所知。