一、and、or：
其实中文意思就可以区分清楚,and是和,并且的意思,or是或者的意思.你搞清楚它们之间的逻辑关系就自然明白了.While作并列连词用,意思为“而,然而”,表对比.而but表转折.注意用心比较体会while与but的句中用意；
二、but、while：
While作并列连词用,意思为“而,然而”,表对比.而but表转折.注意用心比较体会while与but的句中用意
1.Some people waste food while others haven't enough.
有些人很费粮食,然而有些人却吃不饱.
2.The son was having a good meal at home,while the parents were working in the fields.
儿子在家吃好饭而父母却在田里辛勤劳作.
3.I ought to have helped her,but I never could.
我本该帮她但没能.
4.Honey is sweet,but the bee stings.
蜂蜜很甜,但蜜蜂有刺蜇人.