turn out the guard

例句：

1. 1. The decision turned out to be a mistake.
   这个决定最终变成了一个错误。
2. 2. The investigation led to the discovery of a new drug.
   调查导致了新药物的发现。
3. 3. He was responsible for the accident, which turned out to be his fault.
   他应对事故负责，这最终证明是他的过错。