【内容提示】
小孩子全都天真无邪，但并非全都诚实。有好多小孩经常撒谎。小孩撒谎的责任在谁？怪孩子还是怪大人。请你就这一问题写一篇文章，用间接推理的方法论证小孩说谎的原因在家长和老师。
【作文示范】
Why Do Children Tell Lies?
All children are innocent， but not all of them are honest． Quite a few of them tell lies． We frequently hear about children being punished by their parents or teachers for lying． My nephew， an eleven－year－old boy， is often scolded by his mother． Whenever he comes home late， he says that he was at school． But more than once he was found playing with other naughty boys on their way home． Who is to blame now? Is it the children themselves who enjoy telling lies or other people， such as their parents or teachers， who cause them to do so?
We have no doubt that children are born to be pure． They grow up， affected by their surroundings． Although they take interest in almost everything， they haven＇t developed their own powers of independent judgement． They can＇t tell what＇s right or what＇s wrong． Their powers of observation①， in contrast， are much stronger than their powers of judgement． And above all， they are good at imitating②． Unfortunately， we adults sometimes lie． Maybe we find it necessary or have to to do so sometimes． This is something like white lies③． The trouble is that most of us don＇t avoid doing so before children． Thus， children＇s lying is， in a way， the result of adult＇s act．
We also believe that children certainly make mistakes． At first， they do have some interest in truth and honesty． A boy has broken a glass， and have admitted his mistakes； he is almost likely scolded instead of being praised by his parents． And when a pupil admits that he misses class one time， he is usually warned not to do that again another time by his teacher． Gradually the child loses the courage to tell the truth； on the contrary， he feels it helpful to tell lies： at least， he can escape being punished here and now． And at last， he concludes that to tell lies is somehow a good way to get rid of trouble． Before long the parents and the teacher will be complaining that the child is always lying， but they seldom realize that it is they who have brought this on the child．
【词语解释】
①observation n．观察力
②imitate v．模仿
③white lie善意的谎言
【写法指要】
本文在引言段一开头用了一个转折句排除了all中的一部分，接着举了一个具体事例引出一个选择性论点是还是。在正文中，作者运用排他法间接论证了孩子们说谎的两种原因：一是环境影响，二是成人误导。最后得出的结论是：小孩说谎的原因不在孩子本身，而在家长和教师。所以，最后还是用排除法把引言段中的选择性论点确定在还是的强调部分了。所以，我们说，本文从头到尾都是用的排他法间接因果论证。排他法的优点是在对错误观点的逐个否定中加强了自己论点的正确性；在肯定或否定一种情况时，既说明了理由，又比较了优劣，有很强的说服力，使人相信最终的选择是惟一正确的。