Among the most popular books being written today are those which are usually classified as science fiction．Hundreds of 1 are published every year and are read by all kinds of people． 2 some of the most successful films of recent years have been 3 on science fiction stories．
It is often thought that science fiction is a fairly new 4 in literature 5 its ancestors can be found in books written hundreds of years ago．These books often 6 the presentation of some form of ideal 7 －a theme(主题)which is 8 often found in modern stories．
Most of the classics(名著)of science fiction 9 have been written within the last one hundred 10 ．Books by writers such as Jules Verne and H．G．Wells to 11 just two well-known authors have been translated into many languages． 12 science fiction writers don’t write about men 13 Mars or space adventure stories．They are 14 interested in predicting the effect of technical progress 15 society and the human mind, or in 16 future worlds which are a reflection of the world 17 we live in now．
18 of this their writing has obvious political undertones(含义)．In an age when scientific fact frequently 19 science fiction the writers may find it difficult to keep 20 of scientific advances．