the advertisement has been heard ____ five times a day ,which makes people upset

Question

the advertisement has been heard ____ five times a day ,which makes people upset
a.to broadcast b.to be broadcast c.broadcasting d.broadcast
答案d 为什么 a 不对

Answer 1

考非谓语动词
这是一个被动句，分析这种句子一定要还原来看，我们用they作为主语把句子还原成主动句，就是：
They has heard the advertisement_____ five times a day.
我们知道hear有这样三个用法：
hear sb. do sth.,hear sb. doing sth., hear sth. done.
前面两个是主动，最后一个是被动。在这个句子中advertisement和broadcast显然是被动的，所以这里就用broadcast的过去分词形式——还是原形，不变。。。
所以这里就是They has heard the advertisement broadcast five times a day.
要清楚这里broadcast虽然看上去是动词原形，但是事实上它是过去分词形式，变被动的时候不用变化，所以这里选D。

Answer 2

has been been heard 是修饰advertisement的，是后置定语，这里broadcast作广播、播放来理解，过去式、过去分词同形都是broadcast，这里作过去式用，意思是“这则已经被听到的广告一天播了5次了”，选A的话句子就没有动词了

Answer 3

hear sth. done