Hello!
The answer to your questions is C.
Chemicals in the air- olfactory epithelium- olfactory receptors- cilia-olfactory bulb- brain
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Answer: mechanical waves are caused by the disturbance of vibration in matter, whether solid, gas, liquid, or plasma.
Explanation:
Answer:
50 km/hr
Explanation:
150 km devided into 3 hours is 50
Answer:
about 10 trillion kilometers
Explanation:
c = Speed of light = 
t = Seconds in one year = 
1 Light year

The answer is a. about 10 trillion kilometers