Which of the following is/are correct statement(s) regarding mixtures? (select all that apply) A ✓ All substances in a mixture are visible at all times.
В.
Mixtures are composed of a single substance.
C
Substances in a mixture are not chemically combined
D

Mixtures are composed of more than one substance.

Respiratory diseases can be prevented. Avoiding exposure to tobacco smoke, home and workplace air pollutants, and respiratory infections can prevent the development of COPD. Smoking is the most common cause of chronic respiratory diseases like COPD. Smoking cessation is the most important part of treatment for smokers diagnosed with chronic respiratory disease. Indoor and outdoor air pollutants cam also cause respiratory problems. Air pollution can irritate, inflame, or destroy lung tissue. Washing hands regularly with soap and water can prevent respiratory infections. It is estimated that hands spread 80 percent of common infectious respiratory diseases like colds and flu. Early detection of respiratory diseases might change disease course and progress. A simple test, called spirometry can be used to measure pulmonary—or lung—function and detect COPD in anyone with breathing problems.

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