答案:D.
翻译:至于这个项目的实际价值,在人们中仍然还有着相当的怀疑。
解释:
1. remain在此处为系动词“依旧/仍然”,可以视为是be动词is,题目也就演变成下面两句话之间哪个是正确的选择了。
1)It is a certain doubt among the people as to the practical value of the project.
2)There is a certain doubt among the people as to the practical value of the project.
2. 楼上分析基本到位,如果是it is a doubt...的话,则it无所指代。因为后面两个介宾短语among the people和as to the practical value of the project都不是名词性成分,无法做句子的真正主语。
3. 所以,只能理解成there be句型,即“在...(中对于...)有...”。
参考资料:英语牛人团