Answer: Hydrogen bonds are created between the base pairs in DNA. Adenine pairs with thymine and cytosine pairs with guanine. Adenine and thymine create 2 hydrogen bonds while cytosine and guanine create 3. These bonds are fairly weak so that they can be broken when DNA is replicated (by an enzyme called helicase which unwinds DNA). However despite them being weak they do stabilize DNA's double helix structure as well.
Less water-soluble substances will reach the deeper part of respiratory system. That means a substance which more water-soluble(ammonia, formaldehyde, hydrogen chloride) will only damage upper respiratory systems like trachea or bronchus.
High water soluble substance also more irritating.
A whitecap is a wave that is breaking– it is characterized by the white water/foam on the top of the wave.
A swell is a slow, rolling wave that does not have the white water on top. Swells tend to be larger.
Hope that helps!