Epithelial tissue can be according to cell shape and number of layers. one layer of cells is called , and more than one layer is called stratified. thin, flat, scaly cells are . cuboidal cells are either rounded or in shape.

Epithelial tissue is composed of the innervated and avascular layer of cells which are tightly packed. It forms the outermost layer of the body and protects the internal layers and organs.

This tissue can be classified into different categories based on the shape of its cell, and the total number of the layers.

The epithelial tissue with only one layers is known as the simple epithelial tissue.

The epithelial cells that are thin, flat, and scaly are known as the squamous cells.

While the cubodial cells are round or square in shape.

Hence, the given blanks can be filled with classified, simple, squamous, and square.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely