Answer:
i think it is the 3rd one
Is this the end of the question? im not sure what this means
They’ve helped end/calm down pandemics and epidemics and allowed us to go out and start living our life again.
You don’t have to use this word for word just an idea
<span>Observing that fibroblasts grew better in cell culture when blood serum was added to the growth medium instead of blood plasma. Thus proving that there was a substance in serum that made it easier for fibroblasts to grow.</span>
I believe an isthmus is a narrow strip of land connecting two larger land areas.
