The brain i think that is correct
Your answer would be D. Carbon monoxide. Everything else pollutes the water
Two or more organs form together make organ systems.
<u>Explanation:</u>
The basic unit of living organisms is the cell. Multiple cells makes up tissues and tissues make up organs. Two or more organs make up the organ system.
Human body has several organ systems. The organs that make up an organ system can be internal as well as external. Respiratory system is made up of organs like lungs, nose, pharynx, trachea, diaphragm etc. digestive system is made with organs like liver, small intestine, stomach, mouth , large intestine, pancreas etc.
A bone is tissue. It forms a part of the skeletal system which is made up bones, joints, ligaments and cartilage. Cells work together in groups known as tissues. A tissue is defined as a group of similar cells working together to carry out a certain task. Examples are skin, bone, blood. Tissues in turn are grouped together to form organs. An organ is defined as a group of tissues that work together to carry out a certain task . Examples are heart, lungs, liver.
The answer is b because it is negative on our world