He kept waiting for something to happen, some breakthrough to occur.

But it was not until the very end of the caucus that a breakthrough occurred.

The third tunnel, where the breakthrough occurred today, will be for maintenance.

For now, the breakthroughs may well occur in another country.

This is because remarkable breakthroughs have occurred in recent years.

The breakthrough, into large walking passages, occurred on May 26, 1986.

The breakthrough could occur in a matter of days, or years.

After four years of negotiations, a real breakthrough has now occurred.

However, just when the trail seems to be going cold, a dramatic breakthrough occurs.

The final breakthrough in the tunnel occurred on 26 July 2009.