4. A scientist plans to investigate the
nervous system of sea slugs. What
should the scientist do first?
A. Develop a theory about sea slugs
that can be tested.
B. Go to the ocean to observe the
behavior of sea slugs.
C. Obtain several sea slugs and conduct
experiments with them
D. Review the research other scientists
have done on sea slugs.

an electric circuit

im guessing the west of station b

that the claims meet official rules.

don't misinterpret the claims

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 =