These changes have occurred over a long time span.

这些变化经过了很长一段时间才形成。

The project must be completed within a specific time span.

这项工程必须在规定期限内完成。

The time span seems to be much longer than mine.

这段时间看上去要比我长得多。

Enable outgoing synchronization and set the time span.

激活外出性同步化并设置时间跨度。

It just tells the time span of the use of a shape.

呵呵！这只说明了一个形制的源用性的时间跨度问题。