三、完形填空(共20小题;每题1.5分，共30分。)
通读下面的短文，掌握其大意。从每小题的四个选项中选出可填入相应空白处的最佳选择，并把它前面的大写字母填入左边括号里。
If we were asked exactly what we were doing a year ago， we should probably have to say that we could not remember. But if we had kept a book and written in it an account of _31_ each day， we should be able to give an answer _32_ the question.
It is the same in the history. _33_ have been forgotten because we do not have any written account of them. Sometimes men _34_ a record of the important happenings in _35_ country， _36_ often it was destroyed by fire or in a war. Sometimes there was never any written record at all because the people _37_ did not know how to write. For example， we know _38_ the people who lived in China 4，000 years ago， because they could write and _39_ written records for these who live _40_ them. But we know _41_ nothing about the people who lived even 200 years ago in Central Africa， because they _42_.
Sometimes， of course， even if the people cannot write， they may know something of the past. They have learned about it from _43_ people， and often songs and dances and stories have been made about the most important happenings， and these have been sung and acted and told _44_ many generations (後代)。 Most people are proud to tell _45_ their fathers did in the past. This we may call “remembered history”。 _46_ has now been written down. It is not so exact _47_ so valuable to us _48_ written history is， because words are much more easily _49_ when used again and again in speech than copied in writing. But _50_ no written records， such spoken stories are often very helpful.
( )31.A. what to do B. what we did C. how to do D. how we did
( )32.A. for B. in C. on D. to
( )33.A. all things B. Many things C. More D. Much
( )34.A. did keep B. should keep C. would keep D. were keeping
( )35.A. our B. your C. their D. his
( )36.A. still B. but C. even D. or
( )37.A. when and where B. of when and where
C. that time and place D. of that time and place
( )38.A. a good deal about B. a lot of about
C. many D. much
( )39.A. left B. gave C. leave D. send
( )40.A. before B. after C. later D. for