Plz help!!
Choose the word or phrase that best completes each sentence.

Romans developed which allowed engineers to build complex structures and roads.

Romans supplied water to their cities by building

Roman engineers invented the world’s first

1. Romans developed CONCRETE, which allowed engineers to build complex structures and roads.

2. Romans supplied water to their cities by building AQUEDUCTS.

3. Roman engineers invented the worlds firsts FLUSHING TOILETS.

although world war i began in 1914, the united states did not join the war until 1917. the additional firepower, resources, and soldiers of the u.s. to tip the balance of the war in favor of the allies. remaining neutral. when war broke out in 1914, the united states had a policy of neutrality.