例子：

　　History offers many examples ....

　　Past experience has taught people that ....

　　Past two decades witnessed sweeping changes

　　One recent example involves ....

　　According to a recent survey conducted by ..., 27% of college students ....

　　The report indicates that ....

　　A researcher at CSPS(Campus Students’ Problem Society) warns that ....

　　Professor A commented in his epoch-making masterpiece 书名，published in as early as 1993, that ...(with slight abridgement/adjustment/edition of mine)(and I paraphrase). His remarks reveals a universal truth that ....

　　As the Chinese philosopher Kongzi(known as his Latinized name as Confucius)