The two heads of the biceps brachii muscle come together distally to insert on the

1. law of superposition: when there are horizontal layers of rock. the layers at the top are the youngest.

2. law of uncomformity: where one layer is much younger than the previous one, therefore creating a gap in the time record.

3. inclusion: when there is a solid stone inside of another.

4. intrusion: a feature formed when a stone is filled with magma.

hope i answered your question.

during expiration the diaphragm relaxes, which causes the diaphragm to move downwards. the contraction of diaphragm increases the space for expansion of lungs. hence, the diaphragm relaxes and positioned downward during expiration.