externus or superficialis
Their surface is often quenched by the sea water so often at the surface they are, crystals will grow and be visible deeper in the rock.
No, frequency is about how often.
yes
The morning star. Even though it is not a star, and even though it is not always visible in the morning, and is often visible in the evening. -- additional answer -- It is often called "the evening star" also.
Shrimp are crustaceans, animals with a hard shell called an exoskeleton that forms a head, thorax, and abdomen. In shrimp that live near the water's surface, the exoskeleton is often transparent, making them less visible to predators.
Saturn is often called the ringed planet because it has more rings than any other planet in the solar system, and they are the most visible.
Skeletal muscles are found in pairs called flexors and extensors. The flexors bend a joint, and the extensors straighten the joint. Muscles cannot push; they only pull.
a skin
glycogen, often called animal starch
tornado is often made visible by a distinctive funnel-shaped cloud. Commonly called the condensation funnel, the funnel cloud is a tapered column of water droplets that extends downward from the base of the parent cloud. It is commonly mixed with and perhaps enveloped by dust and debris lifted from the surface.
It is usually called bedrock. When bedrock is very close to the surface it is often referred to as ledge.
An eruption of gas in an arc or loop from the solar surface is called a prominence, which is often tied to a brightening of the Sun or "solar flare."