What will happen when all the forests are gone

I don't see the options, but the answer is Loss of biodiversity : Plants and animals will lose their food and shelter. Floods: Bald hills and mountains can no longer hold back sudden flows of water, which cause floods. Increase in carbon dioxide: Depletion of forests results in increase in carbon dioxide, which will cause global warming.

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