但是他补充说,他也不确定。
Mr Suttles said he "did not know for certain" why it had failed.Suttles先生说他“并不十分确定”前种方案失败的原因。
I do not know for certain what the future holds but I am confident that with hard work, a little bit of luck and a supportive network of friends, I can be as successful as I want to be.我不确知未来,但我相信通过艰苦的工作加上一点点的运气和朋友们的帮助,我一定能够心想事成!