It may affect your social life.
Answer:
C
Explanation:
they need balance to stay on track
Vertebrates, and a few invertebrates, have a closed circulatory system. Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities.
Ans/quest:
What’s this for?