The digestive system breaks down food, the respiratory system takes in oxygen, and the cardiovascular system delivers the oxygen and food to the cells.
Answer:
D)radioactive waste is produced
Explanation:
Radioactive waste is a dangerous waste material which contains radioactive substances that are bad for health. These waste are produced in the nuclear reactor for the production of electric energy. Radioactive substances cause many diseases in human such as burning of skin and cancer. It is a non-biodegradable substance which remains in the soil for long periods of time and emit alpha, beta and gamma radiations.
Answer:
<em>D. Molecules are made of atoms of the same element or different elements.
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Explanation:
Molecules are made up of atoms. The atoms forming the molecule can be same or different. The size and function of the molecules vary from each other. The properties and function of atoms change as and when it forms a molecule.
The atoms combine with the help of a bond and it can be a covalent bond or ionic bond or hydrogen bond to form a molecule. The bond between the atoms gives shape to the molecule.
Because back then before pangaea occured the oceans we see today where all one before now they are seperated hope this helps.
