51.be allowed to do sth . 允许做某事
52.pretend to be doing sth.假装正在做某事
53.notice sb doing sth 注意到某人在做某事
54.happen to do sth 碰巧干某事
55.You’d better do ... 意为你最好做……”
56.分数的用法结构为分数+of+the+名词”表示。的几分之几”，当其作主语时，谓语动词的单复数取决于短语中名词的复数
57.时间读法8：21读作twenty-one past eight 或eight twenty –one
58.时间读法8:56 读作four to nine 或eight fifty-six
59.时间读法8:30 读作eight-thirty 或 half past eight
60.名词前如果出现this, that, this, my, Jane’s, some, any等限定词时，其前不能再加冠词。
