doubt没有词根词缀。n. 怀疑疑问疑惑
v. 怀疑不信恐怕拿不准
There is no doubt that he is a hero of our country.
毫无疑问，他是我们国家的英雄。
There was little doubt in my mind.
我心里几乎没有疑问。
There is good reason to doubt this.
有正当理由怀疑这件事。
I doubt the feasibility of the plan.
我怀疑这个计划的可行性。
A doubt niggled at her.
一丝疑惑困扰着她。
There seemed to be no doubt about it.
此事似乎毫无疑问。
