Which part of the crossbow holds the arrow in the track until the trigger is squeezed?

What feature of cell theory is best demonstrated in the image

Fossils can only be formed when? if mud, silt or tar is in the area to preserve the fossil ierosion does not occur and allows the fossil to form oxygen and microorganisms cannot decay the bones the area is dry and does not contain mud or silt

Name the organs of humanelemintary canal.