Question

built to last
how roman harbors have stood the test of time
1
the circular harbor constructed in less than 10 years, at caesarea, which sits on the coast of israel, was king herod, ruler of the roman province of judaea. the site chosen was an unobstructed length of coastline: of judaea. the site chosen was an break the waves rolling into shore or protect ships. the ports construction was nothing short of a roman engineering marvel, comparable to the colosseum or the aqueducts.
2
much of the vast structure, which includes two breakwaters, three underwater piers that once held large statues, and a 60 - foot - wide entrance for ships, stands today. the scholar josephus description, written nearly 2,000 years ago, still rings true: \herod contended with the difficulties so well that the sea could not overcome the solidity of the construction.\
3
the trick to caesareas longevity was the concrete used to build the harbor. for more than a decade, john oleson, a classical archaeologist at the university of victoria, in british columbia, has pursued the secrets of roman harbors and their impressive durability. \people have been studying roman concrete for 500 or 600 years, but they havent done much with the concrete in the sea because its more difficult to access. also, until recently, people thought it was not as important as what you find on land,\ says oleson.
4
as head of the roman maritime concrete study (or romacons), oleson, along with university of colorado boulder maritime archaeologist bob hohlfelder and british architect chris brandon, examined samples from several ancient roman ports. they found that there was, in fact, a key ingredient that made the material uniquely suited to hold up to the underwater environment.
5
the romans started building with concrete regularly beginning in the third century b.c., but the earliest uses go back roughly a thousand years further, to ancient greece.
6
\this contributes more to the economics and
select two excerpts from the passage that together best support the correct central ideas from part a.

1. \people have been studying roman concrete for 500 or 600 years, but they havent done much with the concrete in the sea\ (paragraph 3)
2. \they found that there was, in fact, a key ingredient that made the material uniquely suited to hold up to the underwater environment.\ (paragraph 4)
3. \the romans started building with concrete regularly beginning in the third century b.c., but the earliest uses go back roughly a thousand years further, to ancient greece.\ (paragraph 5)
4. \the romacons team set out to confirm what vitruvius had written by studying the concrete used to build harbors dotting the mediterranean\ (paragraph 7)
5. \all the samples contained volcanic ash that came either from mount vesuvius or campi flegrei\ (paragraph 8)
6. \this contributes more to the economics and

Explanation:

To solve this, we analyze each option:

1. Option 1: The excerpt says people studied Roman concrete for 500 - 600 years but didn’t do much with sea concrete. The central idea of the passage is about Roman concrete’s durability in the sea, so this doesn’t support it. Eliminate.
2. Option 2: The excerpt states the material was uniquely suited to underwater, matching the passage’s focus on Roman concrete’s sea durability. Supports.
3. Option 3: Talks about when Romans started using concrete, not about sea durability. Eliminate.
4. Option 4: The ROMACONS team studying to confirm concrete use in harbors supports the idea of researching Roman concrete’s marine application, matching the passage’s focus. Supports.
5. Option 5: Talks about volcanic ash source, not durability in sea. Eliminate.
6. Option 6: Talks about economics, irrelevant to the passage’s focus on concrete’s sea durability. Eliminate.

Answer:

1. "They found that there was, in fact, a key ingredient that made the material uniquely suited to hold up to the underwater environment." (Paragraph 4)
2. "The ROMACONS team set out to confirm what Vitruvius had written by studying the concrete used to build harbors dotting the Mediterranean" (Paragraph 7)