Answer:
sample A
Explanation:
the first one because of the ppm value
Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change.
When you inhale, air passes through the nasal cavity. There, mucus and hairs clean the air from most foreign particles before entering the body. Then, the air passes from the nasal cavity to the pharynx. After the pharynx, it passes through the larynx reaching the trachea. After passing through the trachea, the air reaches the bronchi, and after the bronchi, the bronchioles that branch off the bronchi. From the bronchioles, the air reaches the alveoli that is when gas exchange happens. O2 enters and CO2 leaves.
I think that a writer may use all of the following techniques to lead the reader to a flashback EXCEPT: a. a memory
