1.   Another tube carries nutrients into a vein.

2.   A bulb forced in water cannot resupply with food for next year, because water carries no nutrients.

3.   Nutrients are carried in a constant flow of water.

4.   Once implanted, the tissue will be infiltrated by blood vessels carrying nutrients.

5.   Bile duct cancer is difficult to operate on because the duct -- which carries nutrients between the liver and the intestines -- extends deep into the organ.