AW 官方范文上得一句话 不太理解

anystoneUID: 3093311

The argument presented above is relativelysound, however, the author fails to recognize all the element necessary to hissituation. The idea that more money be invested inadvertising may be a helpful one, but perhaps not because people are unaware ofthe current reviews. To clarify, it may be necessary to advertise more toincrease sales; however that could be due to many circumstances such as adecrease in the public’s overall attendance, an increase in the cost of movies,or a lack of trust in the opinions of the reviewers.


大家看红色的那部分 后半句but perhaps....， 怎么就没有主语了，主语是什么啊？
请教请教 谢谢谢谢

萝卜须根多UID: 3008387

我的理解是：这个ideas也许有帮助，但也许也没有，因为。。。。

szmanutdUID: 2727152

这句子不需要主语也可以理解的

gfzh1234UID: 3153299

主语是  “the idea"