The term is used to indicate the frequency level of a sound.
a. wavelength
b. overtone
c. amplitude
d. pitch

the current is 0.6

voltage ÷ resistance = current

so 12 ÷ 20 = 0.6

i believe the answer is electric potential.

explanation:

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =