upon的意思除了在...之上外(相当于on,例句:1.He lay down upon[此处也可用on替换] the grass.他躺在草地上。2.The decision was based upon[此处也可用on替换]two considerations.这一决定基于两种考虑。但是upon与on还是有一定区别的,upon通常用于较正式的场合或者once upon a time[从前]和row upon row of seats[一排排的座位,有关此特殊短语的翻译我会在后面提及]等短语中),upon还指某事同时或紧接着发生(也相当于on)。如Upon(此处可与On互换)entering the cabin, she sat down.她一进小屋便...