Blood transfusion and archimedes’ screw: what they have in common

1. Step 1. Blood transfusion — uses — IV drip. A transfusion set.
2. Step 2. IV drip — has part — Syringe. A needle.
3. Step 3. Syringe — has part — Needle. A hollow needle.
4. Step 4. Needle — is part of — Sewing machine. A needle with the eye near its point.
5. Step 5. Sewing machine — has part — Crank. A crank turns rotation into the stroke of the needle.
6. Step 6. Crank — is part of — Archimedes’ screw. A handle or rotary drive.

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