The diagram shows part of a leaf in cross-section. Structures X and Y are both part of the same
A cell.
organ
с
tissue.
D
vessel

a. Cell

Explanation:

This whole diagram is of a plant cell, so X and Y belongs to the cell only.

Hope it helps :)

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.