1.   Dense cloud prevented the rescue helicopter from taking off.

2.   It appears that the Leonids contain a dense cloud of dust released during recent stressful passages of comet Tempel-Tuttle by the Sun.

3.   It flings its fine hairs in the face of the assailant, in a dense cloud.

4.   Standard polyurethane foam ignites rapidly, forming dense clouds of smoke and toxic vapour as it does so.

5.   The acacia grove, like a dense cloud, became a dark backdrop for her.

6.   The Magellan radar-mapping mission was designed to penetrate the dense cloud layer and return detailed radar images of the surface geology.

7.   This shop is surely an outpost of hell, with its oppressive heat and dense clouds of smoke.

8.   Weather satellite images of the area taken from synchronous orbit show an immense circular area of dense clouds above the impact site.

9.   Before long, we emerge from the field, dense clouds cooling the air, promising rain.

10.   Dense cloud cover forced a two-hour delay in the morning and again later in the afternoon.