I like to go skiing in the mountains every winter.

I like to go cross-country skiing in the mountains.

I forgot the ski pole at home.

I forgot my ski pole at home.

The ski slopes are very crowded during the winter holidays.

The ski run\/ski runs\/ski runs are well groomed.

The spark illuminated the dark room.

The light sparkles in the darkness.

Sciatica is very painful.

Sciatica can cause pain along the sciatic nerve.