A. early crawlers become upset when a parent leaves the room. b. when babies start crawling, parents begin to see them as more independent. c. early crawlers become less sensitive to a caregiver's facial expressions. d. parents become more discipline-focused once their babies begin to crawl.

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

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