Final answer:
The statement is true. A cavity wall is made up of two separate walls, or 'wythes', with an air space between them for insulation and to prevent moisture penetration.
Step-by-step explanation:
The statement is true. A cavity wall is indeed comprised of two separate walls, or 'wythes', with an air space between them. This construction method is designed to prevent moisture from outside from penetrating to the inside of the building. The two walls are usually made of brick, block or a similar kind of masonry. The cavity between the wythes helps to improve the insulation of the building and to prevent thermal bridging.
Learn more about Cavity Walls