It's hard to say, but I think you're wrong.

He always used to say, 'It's easy to say, but hard to do.'

He is good at expressing his feelings well.

This library is said to have historical value.

I am very interested in natural science.

I am majoring in information science.

He solved the problem in a scientific way.

He has a wealth of scientific knowledge and is always excited about new discoveries.

He has a deep interest in empirical science.

Earth science is an important field of study for unraveling the mysteries of nature.