正确的应该是存在句句型 there is no/little doubt that …，其中 that 引导的是对抽象名词 doubt 进行具体说明的同位语从句。例如：
～There can be little doubt that he will offend again. 毋庸置疑他还会再犯的。
～There is no doubt, however, that things will improve in the near future. 不过， 毋庸置疑，事情在不久的将来会有所改善。
