The two common iliac veins form the
A) femoral vein.
B) greater saphenous vein.
C) inferior vena cava.
D) hepatic portal vein.
E) innominate vein.
Question 2
Under the influence of the trophoblast, maternal blood vessels in the endometrium
A) disappear.
B) attach to the inner cell mass.
C) break down and form sinuses or lacunae.
D) form a capillary network in the trophoblast.
E) increase in size and penetrate the blastocyst.