这种方法已被科学证明有效。

This method has been ___scientifically proven to be effective.

汽车排放的气体有毒且对环境非常危险，尤其是对臭氧层，这是科学证明且众所周知的。

It is ___scientifically proven and well-known that the gas released by cars is toxic and quite dangerous to the environment, especially to the ozone layer.

研究人员正在科学地研究这一现象，以理解其原因。

Researchers are studying the phenomenon ___scientifically to understand its causes.