I believe 23 I’m not really sure
Answer:
An underground cavern collapsed
Explanation:
I did research
Coal. -from my dad lol ill check
There is a difference between the respiratory system in fetal and adult pigs. The difference lies in the way they conduct respiration. The fetal pig conducts respiration through its umbilical cord when it is still in the mother's womb.
<span>While adult pig conducts its respiration through pulmonary respiration.</span>