分类：教育/科学-外语学习-英语考试
问题：高二英语选择题Tom____betterthantoaskDic 
Tom ____ better than to a Dick for help.A. shall know        B. shouldn't knowC. has known         D. should have known
回答：Tom ____ better than to ask Dick for help. 
A. shall know B. shouldn't know 
C. has known D. should have known
正确答案:D
译文:汤姆本不至于笨到要去请迪克帮忙的程度.
解析:"主语＋should have known better（than to＋原形动词）",意为“本来不应该那样笨,而事实上却很笨去做了...”，是指已经做过的事。例如:
    I should have known better.   我本来不应该那样笨。
    You should have known better than to talk like that.  你本不致于说出这样的话。
    You should have known better than to go mountain climbing alone.你本来不该单独去爬山。