Answer: rolling friction, air resistance.
Explanation:I just took the test on apex
In humans, the yolk sac is the
site of origin for blood cells and primordial germ cells. The human yolk sac is
a membrane located outside the embryo and it is connected by a tube through the
umbilical opening to the embryo's midgut. The yolk sac serves as an early site
for the formation of blood and in time, is incorporated into the primitive gut
of the embryo.
Kingdom Fungi. Mostly are single celled bacteria, they emit sunlight by means of photosynthesis that allows them to make food for themselves and also they have another food serve except for the sunlight and eats some single cell organism and that would call them as heterotrophic
The answer to the first question is a.
Quantitative and systemic data