Issue:

Major decisions should always be left for politicians and government experts to decide. 政府主要的政策应该一切都留给政客和政府专家去做选择。

Reasoning:

They are more informed than the general public. 政客和专家比普通老百姓有更多的信息.

Argument:

科学家作试验，to test whehter the scent of lavender flowers is a natural remedy for insomnia. 然后就解释了一下试验，科学家通过电子仪器在一个controlled的屋子里让volunteers睡觉。(好像是)从第一周开始就用薰衣草味道的针头给大家用。第一周大家都吃了安眠药，第二周没吃，第三周也没吃。 people reported tiredness after first week/ second week they slept longer and more soundly but reported to be less tired than first week/ third week: slept longer and more soundly.

题目问有什么evidence需要futher evaluate whether the scent of lavender flowers is a natural remedy for insomnia.