Three kinds of blood vessels are arteries, vanes and caterpillers. The dodo is a bird that is almost decent by now. To remove air from a flask, fill it with water, tip the water out, and put the cork in quick before the air can get back in. The process of turning steam back into water again is called conversation. A magnet is something you find crawling all over a dead cat.
Bar magnets have north and south poles, horseshoe magnets have east and west poles.
The Earth makes one resolution every 24 hours. The cuckoo bird does not lay his own eggs. To collect fumes of sulfur, hold a deacon over a flame in a test tube. Parallel lines never meet, unless you bend one or both of them. Algebraical symbols are used when you do not know what you are talking about.