20．Language is always changing and developing．（66）C．If English hadn't changed for a long time，we won't have words to describe telephones，washing machines，computers or some other new things．
Language changes for several reasons．（67）B．New technologies，new products，and new experiences need new words to express them clearly．Another reason for change is that different people have different language experiences．People use different sets of words and expressions，（68）E
（69）F On the one hand，many of the languages changes begin with young people．When young people communicate with others of their own age，their language grows in grammar，words and expressions that are different from the older people's．Some have a short lifetime but others can influence the language for long．On the other hand，（70）A．We borrow them from other languages，we create them by making words shorter or combining words and we make them out of proper names．
Languages that don't change over time are considered dead languages．The fact that English changes so much shows that it is alive and well．
A．we get new words in many different ways．
B．First，it changes because the needs of its speaker change．
C．This isn't a bad thing
D．Young people help develop the language．
E．because they have different ages，jobs，education levels（水平） and so on．
F．How does language develop then？
