e sure 确信,肯定 例句: When you start the engine,be sure the car is in neutral. 你在发动引擎时,一定要让汽车处于空档. Can I be sure of a profit if I invest? 我要是投资,肯定能获利吗? He likes to be sure of his bodily comforts. 他注重身体上的舒适. 而Know for sure是指“知道确切的情况；确知”跟know for certain一样. 两者语气不同,前者更加确定,而后者比较偏中性! 再问： 是不是be sure加从句后面+that，know for sure可以直接加从句？
