【简答题】How men first learned to invent words is unknown; in other words, the origin of language is a【B1】______. All we really know is that men, unlike animals, somehow invented certain sounds to【B2】______tho...
【单选题】How man first learnt to invent words is unknown; in other words, the origin of language is a mystery. All we really know is that man, unlike animals, somehow invented certain sounds to express thought...
A.
clearly explained in this passage
B.
a matter that can not be or has not been explained or understood
【单选题】How men first learned to invent words is unknown; in other words, the origin of language is a mystery. (20) All we really know is that men, unlike animals, somehow invented certain sounds to express t...