对于第二点，我不完全肯定。

I'm not so sure about the second.

youdao

专家们如今已经完全肯定那只动物就是美洲狮。

The experts were now fully convinced that the animal was a puma.

youdao

虽然我们不能完全肯定，但是接下来的可能是比较合理的解释。

Although we cannot be entirely sure, the following is probably a fair explanation of what went on.

youdao

So this was definitely in a different generation.

所以那时肯定是个,和现在完全不同的年代。

普林斯顿公开课 - 人性课程节选