We need to ensure a smooth transition between the old system and the new one.

我们得确保新旧制度间的平稳过渡。

Political hopes for a swift and smooth transition to democracy have been dashed.

向民主快速顺利的过渡的政治愿望已经破灭了。

But a smooth transition is another matter.

但能否平稳过渡是另一回事。

He said a smooth transition is his top priority.

他说，平稳过渡是他的首要任务。

He said smooth transition is his top priority.

他说，平稳地移交是他的首要任务。