1.   Balfour slammed his canary-yellow, industrial vacuum truck into gear and roared after the varmint in a cloud of choking brown dust.

2.   As they ran along dusty roads and across fields on the Rwandan shore of Lake Kivu, the fleeing refugees raised a choking dust.

3.   Clouds of choking dust swirl through the Lalla Guzar camp, in which families live in mud huts and tents.

4.   Questions like these, stabbing through the choking black dust of a buried cave, could drive a man mad.

5.   Suddenly, a dust storm rolled over us, filling the air with choking white dust loaded with alkali from the lake bed.

6.   A choking dust swirled in the hot, dry heat.

7.   Rugged terrain, bad roads, choking dust and the coming bad weather of fall and winter could slow the alliance advance.