How to distinguish "over" and "across"? When referring to the sixth edition of the Oxford Advanced Dictionary,we can discover that the first defination of "across"(used as adv.) and the seventh(maybe) defination is exceedingly similar,and yet they are not exactly the same,for we can only use "echoing across the field" rather than over. I would be grateful if somebody could help. ATTENTION!this is not merely a translation
over 意思有: adv.结束, 越过, 从头到尾 prep在...之上, 越过 adj.上面的 vt.额外的东西, 越过 n.额外的东西 做prep.(介词)时的用法 In or at a position above or higher than: 高于…:在…的上方或比…高: a sign ...