Ependyma lines the cavities of brain and spinal cord.

Explanation

### Step-by-Step Solution:

1. **Understanding Ependyma**: Ependyma refers to a type of thin neuroepithelial cells that form a lining. These cells are crucial in the central nervous system.

2. **Location of Ependyma**: Ependyma lines the cavities of the brain and the central canal of the spinal cord. This is a key characteristic of these cells.

3. **Role of Ependyma**: The primary function of ependymal cells is to help in the production and circulation of cerebrospinal fluid (CSF), which cushions the brain and spinal cord.

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