Hollow, that's why birds can fly. There is nothing in the bone to weigh them down.
Answer:
Earth's atmosphere is roughly 78 percent nitrogen and 21 percent oxygen, with trace amounts of water, argon, carbon dioxide and other gases. Nowhere else in the solar system is there an atmosphere loaded with free oxygen, which is vital to one of the other unique features of Earth: life.
Each human has 20 sets of joints, cartilage, ligaments, and bursae.
The correct answer is; sartorius; rectus femoris.
The anterior compartment of the thigh contains the sartorius muscle (the longest muscle in the body) and the quadriceps femous group, which consists of the rectus femoris muscle and the three vasti muscles- the vastus lateralis, vastus intermedius, and the vastus medialis.
They tried to connect the idea of stars with the sun
