What is the presidents role in the lawmaking process?

The president may sign the act of Congress into law, or he may veto it.

Explanation:

After a member of Congress presents a bill into their legislative chamber, the president can decide to sign the bill into law, or they may veto it. Congress can afterwards override a president's veto by a two-thirds vote of both the House and Senate, making the vetoed act a law.

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.