What advantage did concrete barrel vaulting provide in large-scale Roman substructures and sanctuaries?

Identify the monumental complex represented below:  

Why was the arch important in Roman architecture?

This question has two parts:  First identify the tissue section and then write the name one organ where you find this tissue. A is [A]. It is found in [1]. B is [B]. It is found in [2]. C is [C]. It is found in [3]. D is [D]. It is found in [4].

While all other body cavities have bony protection, this cavity does not have  it.

In the picture below, identify the mitotic cell division stages: 1 is [1] 2 is [2] 3 is [3] 4 is [4]

The nervous system is divided into 2 different branches, what are they?

The frontal plane divides the body into ____.

When water sticks to a surface, that represents which property of water?

DNA contains which 4 bases?