Lehman never gave up, though the thought occasionally crossed his mind.

There are two twin species in Europe that occasionally cross.

And we need to know how it might happen that a population could occasionally cross from one side of the knife-edge to the other.

Severe thunderstorms do occasionally cross over the city during the summer.

"If one of us occasionally crosses the boundary between analysis and advocacy, so be it," he said.

Small boats occasionally crossed our line of sight and made silhouettes against the light.

The dancers occasionally cross over from one side to the other and end lined up on the strip of light that once separated them.

There are also wild elephants that occasionally cross over from Myanmar.

Her empathy occasionally crossed the line into sympathy, but that was not necessarily a defect.

"The thought has occasionally crossed my mind," Spock said.