Hydrogen bonds are classified as weak because they are formed fast, but they also break easily under normal biological conditions.
Weak bonds can be easily broken, but this is extremely important because they are in bold in biological systems. For example, they help to decide and stabilize the shapes of water molecules.
<span>Cannot be challenged in court i would say there a law about it</span>
Well, I know 4 is A and 5 is D.
Answer: Four pulmonary veins.
Explanation: Oxygen and nutrient rich blood will flow from the lungs back into this part called the left atrium (Or as some will call it, the left upper chamber in the heart). From there, it goes through four pulmonary veins.
Hope I could help! :)
