(2) They stimulate uncontrolled cell division is your answer. This causes cancer, specifically for lungs, lung cancer.
If your having trouble controlling your heart rate the best thing to do is stop doing what your doing and take 3 deap breaths and the pase back in forth for a short time
A is your answer.
Water containing no salt is known as isotonic solution
Could be the sun but that's just me
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.