Humans' Greatest Achievements

The Earth is 4.5billion years old，but the human race has lived on it for just 200，000years．In that short time，we have achieved some amazing things．

（76） 　 　The list is almost endless．The invention of the airplane has changed our lives．The discovery of antibiotics （抗生素） has saved the lives of millions of people．Can you imagine living without electricity？What about the printing press （印刷术）？Without the printing press，you wouldn't be reading this．In the last 50years，there have been great achievements in communication，such as radio，TV，computers，the Internet，and smartphones （智能手机）．（77） 　 　

What about the arts？The arts have brought pleasure to many people，but are the Beatles and Bach more important than antibiotics？（78） 　 　

Finally，we must not forget humans' early achievements．（79） 　 　We can't imagine modern life without cooked food and cars．

What are humans' greatest achievements？To answer the question，we need to decide what we mean by "great"．（80） 　 　Or is it just something that makes us say "Wow，"like the Great Wall？What do you think？

A．Do you think it is difficult to have great achievements？

B．Is it something that makes us rich or happy or save lives？

C．We enjoy these things every day because they are free to use．

D．They used fire for cooking and heating and invented the wheel．

E．Many of humans' great achievements are in science and technology．

F．And is Mickey Mouse as important an achievement as going to space？

G．We could probably live without them，but life wouldn't be as interesting．