我认为可以肯定地说他将成为下一任总统。

I think it's ___safe ___to ___say that he'll be the next president.

或许可以放心地说，许多技术领域都严重依赖英文出版物。

It is probably ___safe ___to ___say that many technical fields rely heavily on English publications.

鉴于压倒性的证据，可以肯定地说他们的假设是正确的。

Given the overwhelming evidence, it is ___safe ___to ___say their hypothesis was correct.