He waited, observing her profile against the sky and her hair sheening beneath it.

In most cases, the double-beta decay is so rare as to be nearly impossible to observe against the background of other radiation.

It is also often difficult to observe Islamic rules against usury.

Less than a dozen feet away, he observed the detective's hand against the edge of the dim door.

Caitlin observed him closely, against the unpitying stars.

I was just observing some fairly tangible hostility against hummers and their owners.

She stood back mentally for a moment, observing, steeling herself against the pain she knew would be coming.

On 10 October, we will observe World day against the death penalty.

In August 2007 the people of Bakhshali observed a strike against power cuts.