Answer:Stars are formed in clouds of gas and dust, known as nebulae. Nuclear reactions at the centre (or core) of stars provides enough energy to make them shine brightly for many years. The exact lifetime of a star depends very much on its size.
Living things are made of types of molecules, known as macromolecules.
There are four major classes of biological macromolecules:
carbohydrates
lipids
proteins
nucleic acids
Each of these types of macromolecules performs a wide array of important functions within the cell; a cell cannot perform its role within the body without many different types of these crucial molecules. In combination, these biological macromolecules make up the majority of a cell’s dry mass. (Water molecules make up the majority of a cell’s total mass.) All the molecules both inside and outside of cells are situated in a water-based (i.e., aqueous) environment, and all the reactions of biological systems are occurring in that same environment.
What is part B I need more info.
The neurotransmitter is Dopamine.
The following combinations of neurotransmitters seem to be at play in
those who suffer from ADHD is Serotonin, dopamine, and norepinephrine. Neurotransmitters,
also known as chemical messengers, are endogenous chemicals that enable
neurotransmission. They transmit signals across a chemical synapse, such as a
neuromuscular junction.
<span>The question is asking how over-irrigation is damaging to soil. Over-irrigation means that too much water is being delivered to the soil, and too much water can wash some other important ingredients out - such as organic material. Therefore, the correct answer is:
a. It reduces the amount of organic material in soil.</span>
