Scientists can estimate the anthropogenic contribution to global temperature change by comparing recent temperatures to historical values. A physical test for this comparison is done using:

Changes in isotopic oxygen found in ice cores.

Explanation:

It says here that in polar ice cores, the measurement is relatively simple which brings less oxygen in the frozen water meaning the temperature were cooler.

Oxygen isotopes in ice cores extracted from polar regions exhibit a decreasing trend in the ratio of the heavy to light isotopes from the beginning of the Ice Age to its end, at which point the trend reverses sharply and then remains fairly constant for several thousand years.

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.

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.