as sure as a gun

例句：

1. 1. I am as sure as a gun that he will come.
   我确信他会来，就像枪一样确定。
2. 2.The decision was made with the same certainty as if it were a matter of life and death.
   这个决定是以同样确定的方式做出的，就好像这是生死攸关的事情。
3. 3.He was as sure as a gun about his ability to solve the problem.
   他对解决这个问题的能力非常确定，就像枪一样确定。