Oxygen.
Without Oxygen water would not exist.
kutta
Vision and energy
Mind is the second most abundant substance in the human body
napalm
water H2O
The most common substance to all cells are organic molecules. It is carbon that makes for all of life's organic compounds.
The most important substance for maintaining a stable thermal environment within the human body is water.Water is the most important substance for maintaining body temperature.
Jelly.blood and phospholipids
Blood
Calcium, it strengthens bones.
The most important thing for your to remember is that in a physical change the composition of a substance does not change and in a chemical change the composition of a substance does change.
The most important thing in life is to always look on the bright side of it.
Single most (what?) substance ---common? ---important? ---fragile? This question is not formed properly and thus can not be answered
The most important thing in life is to find happiness and fulfillment, whether through relationships, personal growth, or making a positive impact on others. Prioritizing values such as love, kindness, and gratitude can lead to a meaningful and purposeful life.
water air and food are the most important things water, sunlight, and carbon are the most important for life
Some of life's most important virtues are love, respect, and peace. These are important to maintain good relationships and live a happy life.
Water is one of the most important compounds neceesary for life.