A shadow is a surface light cannot touch or reflect off of. Usually shadows appear when the main object is covering a light source. For example, lunar eclipses. Lunar eclipses cause a shadow over Earth because they block the main light source, The Sun from our point of view, casting a giant shadow over Earth.
Explanation:
femur
The femur is one of the most researched bones in the human anatomy and forensic medicine. As the longest bone in the human body, it is well preserved in skeletal remains.
Option C, animals moved from the sea to the land is the right answer.
The Paleozoic Era in the history of the earth was a time of major change on Earth. This was the period that ran about 542 to 251 million years ago. The period commenced with the split of a single super-continent and the development of another. Plants grew extensively. Moreover, the primary vertebral animals conquered the land.
