Which of the following is contained in a bicycle?
a. gears and inclined plane.
b. inclined planes and screw.
c. wheel and axle and screw.
d. wheel and axle and inclined plane.

i think the answer is a and b

i wish you luck

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 =