完全没有理由怀疑他的诚意。

There is ___no reason ___whatsoever to doubt his sincerity.

这次会议根本没有提供任何智力上的启发。

The meeting offered ___no intellectual stimulation ___whatsoever.

尽管进行了广泛研究，科学家们完全没有发现那个古代文明的任何踪迹。

Despite extensive research, scientists found ___no trace ___whatsoever of the ancient civilization.