Most of the heat from the sun warms the Earth's surface through A tradition B conduction C convection

ill do it for 100, also this isnt 80 its 40

mass and volume are the answers you are looking for

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 =