Select anniversary have annual festivals to commemorate previous significant occurrences.

The town is known to have a significant occurrence of ilmenite, a weakly magnetic mineral containing titanium oxide.

And I found a significant occurrence of fullerenes.

Infanticide only came to be seen as a significant occurrence in nature quite recently.

This was to be a significant occurrence regarding the future of Chris Swailes.

Several significant occurrences followed the Armenian Genocide of 1915 to 1917.

A series of continuous tornado outbreaks is known as a tornado outbreak sequence, with significant occurrences in May 1917, 1930, 1949, and 2003.

Here's where you get to make predictions about a significant occurrence in any corner of the world related to the Net.

This in turn caused the much broader digital revolution, one of the most significant occurrences in the history of humankind.

This period of sick leave was one of the most significant occurrences in MacMahon's life.