Please explain what an enzyme is, to me in the simplest yet shortest way possible thx .-. and clearest yet easiest explanation GET BRANIET and here are some free 32 points!

They are proteins that act as biological catalysts.

first, the romans stayed isolated because they had to defend their own territories from neighboring cities that were harassing them, like the etruscans. second, once the romans managed to defeat their neighbors, and started to expand their territory, they started to build roads and bridges. finally, now that the romans have covered their territory with roads functioning as highways, they could mobilize their legions faster to assemble larger military units in a specific place.

answer; i believe the correct answer is (4) flip a coin as each participant arrives,heads indicates assignment to the first group: tails indicates assignment to the second group;