Question

which of the following is necessary for hearing to occur?noises above 80 decibalsvibrations in the airboth ears working togetherwhich two senses are called chemical senses?sight and hearingsmell and tastesight and smelltaste and hearing

Explanation:

• For the first question: Sound is produced by vibrations. Vibrations in the air (sound waves) are necessary for hearing. Noises above 80 decibals are not necessary (we can hear softer sounds), and we can hear with one ear (though localization is harder).
• For the second question: Smell (olfaction) and taste (gustation) are chemical senses. They detect chemical substances (odorants for smell, tastants for taste). Sight detects light, hearing detects sound waves (mechanical in nature).

Answer:

• First question: vibrations in the air
• Second question: smell and taste