Stalactites
That tree is hollow. Do you have a hollow leg? I'm going to hollow out a hole.
Your response rings hollow.
His ardent plea rang hollow.
Mosses do not have tubes for moving nutrients and water. They also do not have any true leaves, stems, or roots. Nonvascular plants also do not have transport tubes.
A conical tube is a hollow triangular shaped receptacle often used in laboratories. Conical tubes are used in centrifuges where specimens are spun at high speeds to separate the particles they are made of.
Hollow tubes is an redundant expression. Tubes must be hollow, by definition. However tubes can be filled with something so they are not "empty" (they still will be hollow).
For the same amount of metal, hollow tubes are much stronger than solid tubes.
Microfilaments are thinner rods of protein that enable movement. Microtubules are hollow tubes that give rigidity and shape. Flagella and cilia have microtubules in their centers.
A capillary is hollow. It is the smallest of the blood vessels, the tubes that carry blood.
Microtubules consists of hollow tubes which provide support of the cell.
IPS tubes are bus tubes where the current is carried through AL / Cu tubes (Hollow inside) and ACSR conductor are conductors basically with no any hollow part inside. Bus tubes given hollow portion inside taking in consideration greater skin effect to the current they carry -Anand Girgaonkar
microtubules
cytoskeleton
Xylem are just made up from cell walls left from cells, making hollow tubes. The walls of these tubes are hydrophilic, so water attaches readily to them, helping it to climb on its way up the plant.
astral ray
Cilia.
microtubules