Final answer:
A Continental Arctic (cA) air mass is correctly described as cold and dry, often originating over polar regions, and is known for its very cold temperatures and dry air.
Step-by-step explanation:
The correct answers for a Continental Arctic (cA) air mass are:
- Cold and dry
- Often originates over polar regions
A cA air mass is characterized by its very cold temperatures and dry air. It usually forms over polar regions, where it acquires its frigid properties. However, while a cA air mass can lead to cold weather conditions, the term "severe weather conditions" typically refers to more dynamic weather phenomena, such as storms, which are not specifically associated with cA air masses.