What are the two ways to achieve a tube within a tube body plan?

Which of the following has pseudocoelomate tube within a tube body plan

What happened to the water level in the capillary tube?

Fusion of one male gamete with egg and other of the same pollen tube with two polar nuclei is

Arrange capillary tubes of different diameter on a piece of thermocol. Dip the capillary tubes in water. Compare the capillary rises in the tubes. How is the diameter of the tube and capillary rise related? .