The boy always stays there for________．
A.one and half hour
B.one and a half hour
C.one and half hours
D.one and a half hours
网友回答
D解析分析：“一个半小时”的正确表达是one and a half hours＝an hour and a half，而“半小时”的正确表达是half an hour(也可以说a half hour)(延伸)时间、度量衡单位都可以用这种方式来表达：two and a half months＝two months and a half，但在用or时要这样表达：“一、二个小时”one or two hours/an hour or two．