I didn't think he would come.

He is an expert in systems engineering.

Our school has introduced a new PA system.

The filesystem of my computer has broken down.

When I hear that song, old memories come to mind.

This was truly an unexpected result.

I am surprised by this unexpected event.

His thoughts were as we expected.

The automotive navigation system in my car has downloaded the latest map data.

Geographic Information Systems are very useful tools for map making and spatial data analysis.