AD的解释
abbr. (advertisement的缩写)广告
n. (缩)广告
AD的例句
I got four replies to my ad about the bicycle for sale.
已经收到了四份对我出售自行车广告的回信。

Fished all day without a bite; an ad that got a few bites but no final sales.
一整天没半条鱼上钩；这则广告吸引了一些人上钩，但最后还是没有卖出东西