the boy always stays here for(?) a.one and a half hour b.one and a half hours 选哪个?为什么?
问题描述：
the boy always stays here for(?) a.one and a half hour b.one and a half hours 选哪个?为什么?
答
选b
一个半小时（即90分钟）,有多种表达方式：one and a half hours,one hour and a half或者an hour and a half都可以.因为一个半小时超过了一个小时,所以one and a half后面跟复数hours,而one后面是hour,加单数,加上 and a half.