one hour和an hour,两个是无差别的吗?
one hour和an hour,两个是无差别的吗?
an hour one hour
是a one-hour ducumentary还是an one-hour documentary
more than one hour和more than an hour区别
a one -hour还是an one-hour
an hour early 和 an hour earlier 的区别?
in an hour和within an hour的区别
one hour and a half是错的吗?老师说只能用an hour and a half,如果不行,是语法规定的
an hour的不定冠词为什么是an
One and a half an hour 和An hour and a half 有什么不同
是half hour还是half an hour?
冠词 an one-hour 还是a one-hour