Tens of thousands of years ago, before the development of written languages, ancient humans drew pictures of animals on cave walls and decorated them with markings, which appear to have been an early form of symbolic communication.
30 What can we learn from Dr. Neil Cohn’s words?
选项：

A:Emojis are a basic form of our written language from an evolutionary perspective.
B:Written language is the norm of our communication different from speaking language.
C:The gesture we make when we talk is the essence of our daily communication.
D:Emojis and written language are a complement to each other in communication.