Answer:
Tubercle: allows tendons to attach to bone
Foramen: Allows blood vessels and nerves to travel through bone.
Fossa: Allows to bones to form a joint.
Explanation:
The tubercle or tuberosity in the human seletal system, is a protrusion that allows for attachment of skeletal muscles. The muscles attach by tendons, where the enthesis is the connective tissue between the tendon and bone.
Foramina inside the body of humans and other animals typically allow muscles, nerves, arteries, veins, or other structures to connect one part of the body with another.
Swamps or maybe those in the desert. In swamps, the soil is too loose for animals to burrow without it caving in. In deserts, since the climate "rising" its getting to hot and dry for animals to burrow without the sand caving in when an animal walks above it.
What is different with retroviruses in reproduction is that they do not kill their hosts at first because they can still insert their own genome. This process is what is known the reverse transcription. This is done by different proteins.
