Gansu province vs mainland China

Gansu province and mainland China both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gansu province	Yes	No	No	No
mainland China	Yes	No	No	No

Gansu province (noun)	mainland China (noun)
a province in north-central China; formerly part of the Silk Road to Turkistan and India and Persia	a communist nation that covers a vast territory in eastern Asia; the most populous country in the world