Questions

The Early Middle Ages have often been called the Dark Ages, and to some extent  they were truly dark. The people led a miserable life. Education was very uncommon. The helplessness of the comman man the arbitary rule of the king and the barons and the absence of national unity-all these conditions were common in Europe. The term 'Middle Ages' does not cover a uniform period for all the countries of the world.For Europe and the Westren World , the 'Middle Ages' are generally considered to be the period between AD 500 and AD 1500.

The nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body.

In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body.

The nervous system has three main functions:

* To collect sensory input from the body and external environment.

* To process and interpret the sensory input.

* To respond appropriately to the sensory input.

Epithelial tissue is made of layers of cells that cover the surfaces of the body that come into contact with the exterior world, line internal cavities, and form glands.

The four types of tissue in the body are epithelial, connective, muscle, and nervous. 

Br-Br.

In Br2, two of the same atoms, pull on each side of the bond is equal making it as non-polar.

The other options all include a significantly more electronegative atom (the oxygens and the chlorine), so those bonds are all polar covalent.