1.?? ????,?????? back off 躲開,讓開,隨退

?:??? ? ?? ?? ??????.
ex:The mugger backed off when he saw my dog.
例: 強盜一見到我的狗就躲開了。
2.-? ????? back up 支持,援助
?:?? ??? ??? ???.??? ??? ?? ??? ?? ??? ????? ????.
ex:He is telling the truth;all the evidence we have backs up his claim.
例:他說了實話,我們所有的證據都對他的主張有利。
3.~? -?? ?? ???? bar~from doing 禁止做…
?:???? 21? ??? ?? ?????? ?? ?? ???? ??.
ex:State law bars anyone under 21from buying alcoholic beverages.
例:洲法律禁止未滿21周歲者購買酒類飲料。
