A water strider sits on the surface of a pond. This occurs because

their legs contain specialized hairs that are able to repel the water and to capture the air

Explanation:

The water strider is one of the most common aquatic insects. Water striders can sit on the water surface due to they have specialized hydrophobic water-repelling hairs in their legs that allow them to use the surface tension of water in order to distribute the weight. Thus, the hairs in the legs of these insects enable them to float and move on the water surface.

answer;

-vessels in the chest

the diagnosis of angina pectoris literally means "vessels in the chest"

explanation;

-angina pectoris is the medical term for chest pain or discomfort due to coronary heart disease.it is the chest pain due to an inadequate supply of oxygen to the heart muscle. the pain is typically severe and crushing, and it is characterized by a feeling of pressure and suffocation just behind the breastbone.

agina pectoris is caused by reduced blood flow to your heart muscle. the blood carries oxygen, which the heart muscle needs to survive. when the heart muscle isn't getting enough oxygen, it causes a condition called ischemia