Cats are digitigrade animals, they walk on their toes.

He learned about unguligradism in his zoology class.

His research mainly focuses on the plantigradism of mammals.

She has polycystic ovary syndrome.

He is writing a thesis on monotheism.

Sufficient caution is necessary when handling radioactive materials.

He is exactly in the state of 'A frog in a well does not know the vast ocean.'

He spoke of his big dreams, saying, 'How can a sparrow understand the ambitions of a swan?'

General relativity is a theory of physics proposed by Einstein.

Special relativity is one of the fundamental theories of physics.