Scientists ________ that the secret to Roman concrete's durability was its unique blend of ingredients, which included volcanic ash and seawater.<br/><br/>Which choice completes the text so that it conforms to the conventions of Standard English?
MM
Mashaal Masha
Jan 09, 2024
Why are Rome’s famous concrete structures, such as the Colosseum, still standing after 2,000-plus years, when modern concrete may not even last for fifty?Scientists ________ that the secret to Roman concrete's durability was its unique blend of ingredients, which included volcanic ash and seawater.
Which choice completes the text so that it conforms to the conventions of Standard English?