Despite the fact that they were on a smooth path she stumbled once or twice.

The result is that he stumbled twice when the pressure of history was upon him.

I only stumbled once or twice, tripping over boulders on the floor.

I stumbled twice, fell forward, scraping my knees and elbows.

She walked slowly east toward it, stumbling once or twice before she started to pay proper attention.

It raced clumsily across the ground, stumbled once or twice, and launched itself into the air.

He made his way in the dark, stumbling once or twice.

I saw him stumble twice, but he carried on, more slowly than before.

The smaller man hit the ground hard, rolled, came to his feet, stumbled twice, then charged in.

She detached herself from the railing one hand at a time, and half ran around the pond, stumbling twice.