look at sth,是指看著某物,強(qiáng)調(diào)動(dòng)作. 比如,look at me~看著我
look就是普通意義上的看,單獨(dú)使用,不加sth.比如,look,there's a dog~ 看,那有一條狗~
最后一個(gè)have a look ,后面應(yīng)該加at sth,have a look at sth是詞組,意思是看一下某物,比如have a look at that woman,看一下那個(gè)婦女~