Name the structures marked 1, 2, 3 in these images of a three-vessel view of a normal fetal heart in the third trimester.

1- ascending aorta, 2- superior vena cava . 3- descending aorta

1- ductus arteriosus; 2- ascending aorta ; 3- superior vena cava

1- inferior vena cava; 2- descending aorta; pulmonary vein

1- superior vena cava; 2- ascending aorta; 3- pulmonary artery

1- ductus arteriosus; 2- superior vena cava; 3- ascending aorta

1- ductus arteriosus; 2- ascending aorta ; 3- superior vena cava 

The structure towards the left is the ductus arteriosus emerging from the pulmonary trunk. The structure in the middle is the ascending aorta. The structure towards the right is a superior vena cava.