Shelters often become extremely overcrowded because of long and sometimes unpredictable intervals between buses.

At unpredictable intervals the inscriptions fade and new ones appear.

That winter, Francisco came to see her in New York, at unpredictable intervals.

The shocks now came at irregular, unpredictable intervals, one after another or minutes apart.

Mass and energy seem to be coming and going at unpredictable intervals.

And everything, of course, must come to a stop at unpredictable intervals, as a beam is pulled up and human remains suddenly surface.

Because they pipe up at unpredictable intervals, you get the slightly hair-raising feeling that each has its own consciousness.

He would have to pass between two huge mountains that, at unpredictable intervals, suddenly leaned and ground together.

Life was all about moving on at random and unpredictable intervals.

It's good to be in the halls at unpredictable intervals at such times, by the way.