Which sentence best states the main idea of the passage?

A corroded lump from a shipwreck turned out to be a complex ancient machine that still raises questions (The passage moves from an ignored lump, to what the machine did, to the open question it leaves behind.)

According to the passage, what did the dials show?

the sun and moon, the moon's phases, and coming eclipses (The second paragraph lists exactly these three functions.)

'corroded' describes metal that has been

damaged and eaten away over long exposure (The metal is 'shapeless' and later has 'corrosion' hiding its writing, so the word means slowly eaten away, not cleaned or struck.)

The Machine In The Wreck: Level 3 Reading Comprehension Questions

Q: What does the writer suggest about the mechanism?

It was probably not the only machine of its kind ('If someone could build this, similar machines almost certainly existed' says the skill was not a single accident, so other machines are likely.)

In 1901, sponge divers sheltering from a storm anchored near the small Greek island of Antikythera. Under the water they found an ancient shipwreck loaded with bronze and marble statues. Among the cargo was a shapeless lump of corroded metal, about the size of a thick book. It sat in a museum for months before anyone noticed the gear teeth inside it.

The lump is now called the Antikythera mechanism, and it is roughly two thousand years old. More than thirty bronze gears survive, cut by hand and fitted together in layers. When the handle was turned, pointers moved across dials on the front and the back. The dials tracked the sun and the moon, showed the phases of the moon, and predicted eclipses years ahead.

Nothing else of that quality has been found from the ancient Mediterranean world. Modern imaging has read faint inscriptions hidden under the corrosion, a kind of instruction manual for the device. Yet the mechanism raises a hard question. If someone could build this, similar machines almost certainly existed. Either they were lost, melted down for their metal, or they are still lying somewhere underwater.

Comprehension questions